WorldWideScience

Sample records for sublethal biological effects

  1. Lethal and Sublethal Effects of Fenpropathrin on the Biological Performance of Scolothrips longicornis (Thysanoptera: Thripidae)

    DEFF Research Database (Denmark)

    Pakyari, Hajar; Enkegaard, Annie

    2013-01-01

    Determination of negative nontarget effects of pesticides on beneficial organisms by measuring only lethal effects is likely to underestimate effects of sublethal doses. In this study, the sublethal effects of fenpropathrin on the predatory thrips Scolothrips longicornis Priesner (Thysanoptera: T...

  2. Sublethal Effects of Insecticide Exposure on Megacopta cribraria (Fabricius) Nymphs: Key Biological Traits and Acetylcholinesterase Activity.

    Science.gov (United States)

    Miao, Jin; Reisig, Dominic D; Li, Guoping; Wu, Yuqing

    2016-01-01

    Megacopta cribraria F. (Hemiptera: Plataspidae), the kudzu bug, is an invasive insect pest of U.S. soybean. At present, insecticide application is the primary and most effective control option for M. cribraria In this study, the potential effects of sublethal and low-lethal concentrations (LC10 and LC40) of three common insecticides on key biological traits and acetylcholinesterase (AChE) activity of the treated nymphal stage of insect were assessed. The results show that the sublethal concentration of imidacloprid significantly reduced adult emergence rate of M. cribraria A low-lethal concentration of imidacloprid significantly increased nymphal development time, but significantly decreased adult emergence rate and adult longevity. Both sublethal and low-lethal concentrations of acephate caused an increase in nymphal development time and a reduction in adult emergence rate and adult longevity. Fecundity of females was significantly reduced only by exposure to low-lethal concentrations of acephate. Sublethal and low-lethal concentrations of bifenthrin increased nymphal development time, but significantly decreased adult emergence rate. In addition, we found that the AChE activity of M. cribraria was significantly increased only by LC40 imidacloprid, but strongly inhibited by acephate. © The Author 2016. Published by Oxford University Press on behalf of the Entomological Society of America.

  3. Sublethal effects of contamination on the Mediterranean sponge Crambe crambe: metal accumulation and biological responses

    International Nuclear Information System (INIS)

    Cebrian, E.; Marti, R.; Uriz, J.M.; Turon, X.

    2003-01-01

    The effect of low levels of pollution on the growth, reproduction output, morphology and survival of adult sponges and settlers of the sponge Crambe crambe were examined. We transplanted sponges from a control area to a contaminated site and measured the main environmental variables (chemical and physical) of both sites during the study period. Except some punctual differences in particulate organic matter, silicates, nitrates, and water motion, most environmental variables in the water were similar at both sites during the study months. Mainly copper, lead and OM concentrations in the sediment, and water motion were significantly higher at the polluted site and may be implicated in the biological effects observed: decrease in the percentage of specimens with embryos, increase in shape irregularity and decrease in growth rate. Individuals naturally occurring at the polluted site and those transplanted there for four months accumulated ten times more copper than either untouched or transplant controls. Although lead concentration in sediment did not differ between sites, native specimens from the contaminated site accumulated this metal more than untouched controls. Vanadium concentration also tended to increase in the sponges living at or transplanted to the contaminated site but this difference was not significant. C. crambe is a reliable indicator of metal contamination since it accumulates copper, lead and vanadium in high amounts. At the contaminated site, sponge growth, fecundity and survival were inhibited, whereas sponge irregularity ending in sponge fission was promoted. All these effects may compromise the structure and dynamics of the sponge populations in sheltered, metal-contaminated habitats

  4. Sublethal effects of a metal contamination due to uranium mine tailings in the three-spined stickleback (Gasterosteus aculeatus L.). Implication in the susceptibility to a biological stress

    International Nuclear Information System (INIS)

    Le Guernic, Antoine

    2015-01-01

    Uranium extraction has resulted in a remobilization of this actinide into mine surrounding ecosystems. Uses of metal salts during mining site rehabilitation, and the natural presence of metals have increased the metal contamination in hydro systems submitted to mine tailings. In situ experiments were conducted in two former French uranium mining sites. Three-spined stickleback caging was used to determine the sublethal effects of this metal mixture on this freshwater fish, as well as its effects on fish susceptibility to a sudden biological stress. This pollution, characterised by higher metal concentrations (especially for uranium), has led to an oxidative stress in sticklebacks visible through several bio-markers, and other effects dependent on the study site. The polymetallic contamination has modified the stickleback responses to the biological stress, by preventing their phagocytic and antioxidant responses. This work has reinforced the interest of the caging technique during environmental studies and that of immuno-markers in a multi-bio-marker approach. (author)

  5. Sublethal Effects of Essential Oils From Eucalyptus staigeriana (Myrtales: Myrtaceae), Ocimum gratissimum (Lamiales: Laminaceae), and Foeniculum vulgare (Apiales: Apiaceae) on the Biology of Spodoptera frugiperda (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Cruz, G S; Wanderley-Teixeira, V; Oliveira, J V; Lopes, F S C; Barbosa, D R S; Breda, M O; Dutra, K A; Guedes, C A; Navarro, D M A F; Teixeira, A A C

    2016-04-01

    Spodoptera frugiperda (Smith 1797) (Lepidoptera: Noctuidae) is a major pest of maize, Zea mays L. Its control is often achieved through repeated applications per season of insecticides, which may lead to adverse effects on the ecosystem. Thus, the study of alternative methods with less environmental impact has expanded to include the use of essential oils. These oils are products of the secondary metabolism in plants, and their insecticidal activity has been widely demonstrated in populations of many pest insects. This study evaluated the insecticidal activities of essential oils from Eucalyptus staigeriana, Ocimum gratissimum, and Foeniculum vulgare on Spodoptera frugiperda. Gas chromatography–mass spectrometry profiles and contact toxicity of these oils as well as their sublethal effects on larvae and reproductive parameters in adults were evaluated. All three oils had sublethal effects on S. frugiperda; however, the oil of O. gratissimum showed the best results at all doses tested. These essential oils may have promise for control of S. frugiperda.

  6. The sublethal effects of zinc at different water temperatures on ...

    African Journals Online (AJOL)

    The sublethal effects of zinc at different water temperatures on selected ... of 96h at different water temperatures representing the seasonal temperatures in the ... are mobilised to meet increased energy demands during periods of stress.

  7. Sublethal effects of some synthetic and botanical insecticides on Bemisia tabaci (Hemiptera: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Esmaeily Saeideh

    2014-07-01

    Full Text Available In addition to direct mortality caused by insecticides, some biological traits of insects may also be affected by sublethal insecticide doses. In this study, we used the age-stage, two-sex life table method to evaluate the sublethal effects of the four synthetic insecticides: abamectin, imidacloprid, diazinon, and pymetrozin as well as the botanical insecticide taken from Calotropis procera (Asclepiadaceae extract, on eggs of the cotton whitefly, Bemisia tabaci (Hem.: Aleyrodidae. The lowest and highest survival rates and oviposition periods were observed in whiteflies treated by diazinon and imidacloprid, respectively. We found significant differences in the net reproductive rate (R0, the intrinsic rate of increase (r, the finite rate of increase (?, and the gross reproductive rate (GRR among different insecticides. Altogether, our results showed that pymetrozin and C. procera induced the most sublethal effects, thus they may be suitable candidates for use in integrated pest management programs of B. tabaci.

  8. Sublethal effects of tritium on aquatic systems

    International Nuclear Information System (INIS)

    Strand, J.A.; Poston, T.M.

    1982-01-01

    It is the purpose of this continuing study to determine the relative biological effectiveness (RBE) of 3 H-beta irradiation when compared to 60 Co-gamma irradiation applying the relatively radiosensitive immune process of the rainbow trout, Salmo gairdneri. This study is also designed to investigate the nature of latent expression of immune incompetence in trout exposed to 3 H-irradiation during embryogenesis

  9. Histopathological effects of lethal and sub-lethal concentrations of ...

    African Journals Online (AJOL)

    The histopathological effects of lethal and sub-lethal concentrations of glyphosate on African catfish Clarias gariepinus were investigated. C. gariepinus juveniles were assessed in a static renewal bioassay for 96 hours (acute toxicity) and 28 days (chronic toxicity) using varying concentrations (0.0 mg/l 20.0 mg/l, 30.0 mg/l, ...

  10. Toxic effects of sublethal concentrations of diethyl Phthalate on the ...

    African Journals Online (AJOL)

    An investigation on the effect of Diethyl phthalate (DEP) on the gill of the African catfish Clarias gariepinus was carried out in the laboratory. Seventy-five (75) catfish fingerlings were subjected to continuous exposure to sublethal concentrations of DEP (30, 40, 60 and 80 ìg/L) for a period of four weeks. The gills of the catfish ...

  11. Effects of sublethal doses of chlorfluazuron on the ovarian ...

    African Journals Online (AJOL)

    AJB_YOMI

    2011-10-12

    Oct 12, 2011 ... eggs (Perveen, 2000a). The objectives of this research were to determine the effects of sublethal doses of chlorfluazuron (LD10or LD30) on the amounts of ovarianprotein, lipid, carbohydrates, DNA, and RNA, and ecdysteroid titres in different developmental stages of S. litura, a major crop pest around the ...

  12. Pesticides and Arthropods: Sublethal Effects and Demographic Toxicology

    Directory of Open Access Journals (Sweden)

    Dejan Marčić

    2007-01-01

    Full Text Available Insecticides and acaricides designed to control primary harmful insects and mites may also variously affect some other arthopods present in an (agroecosystem (e.g. secondary pests, predators, parasitoids, saprophytes, bioindicators, pollinators. Apart from insecticides and acaricides, arthropods may also be affected by the activity of other pesticides (fungicides, herbicides, etc.. Regardless of whether they are deemed desirable or not, the effects that pesticides have on arthopods need to be quantified as closely as possible through appropriate experimental procedures. Data acquired in tests designed to determined LD50/LC50 values are inadequate for evaluation of pesticide effectiveness in the field as pesticidesalso cause various sublethal effects, generally disregarded in such investigations. The sublethal effects of pesticides refer to any altered behaviour and/or physiology of individuals that have survived exposure to pesticides at doses/concentrations that can be lethal(within range causing mortality in an experimental population that exceeds mortality in an untreated population or sublethal (below that range. Pesticides affect locomotion and mobility, stimulate dispersion of arthropods from treated areas, complicate or prevent their navigation, orientation and ability to locate hosts, and cause changes in their feeding, mating and egg-laying patterns. Sublethal pesticide effects on arthropod physiology reflect on the life span, rate of development, fecundity and/or fertility, sex ratio and immunity of surviving individuals. Different parameters are being used in arthropod bioassays to determine sublethal effects (ED50/EC50, LOEC, NOEC, total effect index. Compared to acute toxicity tests, these parameters improve the quality of evaluation and create a more accurate view of the effects of a pesticide. However, such approach covers mainly fecundity/fertility alone, while all other sublethal effects remain unaccounted for. Besides, it

  13. Sublethal Effects of Fenoxycarb on the Plutella xylostella (Lepidoptera: Plutellidae).

    Science.gov (United States)

    Mahmoudvand, Mohammad; Moharramipour, Saeid

    2015-01-01

    The effects of fenoxycarb, a Juvenile hormone analogue, at sublethal concentrations were tested on some biological parameters of Plutella xylostella (L.) in two consecutive generations. The calculated LC10, LC25, and LC50 values of the insecticide were 21.58, 43.25, and 93.62 mg/liter on third-instar larvae, respectively. Fenoxycarb significantly reduced pupal weight and oviposition period in parent generation. In addition, the fecundity of treated groups (LC10 = 71.06, LC25 = 40.60 eggs per female) in parents was significantly lower than control (169.40 eggs per female). Although fenoxycarb could not affect gross reproductive rate and death rate, it decreased net reproductive rate, intrinsic rate of increase, finite rate of increase, and birth rate in offspring generation. Also, mean generation time and doubling time of treated insects was significantly longer than control at LC10 level. Therefore, the data from this study suggested that fenoxycarb could adversely cause population decline in the subsequent generation. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

  14. Sublethal effect of neem extract on mediterranean fruit fly adults

    Directory of Open Access Journals (Sweden)

    Márcio Alves Silva

    2013-03-01

    Full Text Available The sublethal effect of extracts of Azadirachta indica on Ceratitis capitata was evaluated. Two pairs of flies were treated in plastic tubes with cotton placed in plastic cages. An artificial diet (hydrolyzed protein + sugar was provided ad libitum. The extracts affected significantly the longevity of C. capitata. The pre-oviposition period were not significantly affected by the extracts. The A. indica branches extracted with dichloromethane (888 ppm affected significantly the fecundity and fertility, reducing the number of eggs laid to approximately 80 % and the egg hatching by 30 % at the 8th day. Therefore, the neem branches extracted with dichloromethane affected the reproduction of C. capitata.

  15. Sublethal Toxic effects of spent Oil Based Drilling Mud and Cuttings ...

    African Journals Online (AJOL)

    Sublethal toxic effects of spent oil based drilling mud collected from an abandoned oil drilling site in Mpanak, Akwa Ibom State, Nigeria were assessed in the earthworm Aporrectodea longa. The test annelid was exposed to sub-lethal Concentration of 0ppm SPP; 62,500ppm SPP; 125, 000ppm SPP; 250,000ppm SPP and ...

  16. Effects of Sublethal Concentrations of Insecticides on the Functional Response of Two Mirid Generalist Predators.

    Directory of Open Access Journals (Sweden)

    Angeliki F Martinou

    Full Text Available The use of agrochemicals particularly pesticides, can hamper the effectiveness of natural enemies, causing disruption in the ecosystem service of biological control. In the current study, the effects of the insecticides thiacloprid and chlorantraniliprole on the functional response curves were assessed for two mirid predator nymphs, Macrolophus pygmaeus Rambur and Nesidiocoris tenuis Reuter. In the absence of insecticides, both predators exhibited a type II functional response when feeding on eggs of the moth Ephestia kuehniella. N. tenuis seems to be a more efficient predator than M. pygmaeus, as model estimated handling time was significantly lower for the former than for the latter. Residual exposure of M. pygmaeus to sublethal concentrations of either insecticide was associated with a change in the asymptote but not the type of the functional response curve. Thiacloprid seems to be the least compatible with M. pygmaeus, as it led to both a significant reduction of the attack rate and an increase in handling time. In contrast, chlorantraniliprole exposure significantly increased the handling time, but not the attack rate of the predator. Residual exposure of N. tenuis to sublethal concentrations of either insecticide did not have a significant effect on the type nor the parameters of the functional response model. The results show that pesticide residues that do not have lethal effects on beneficial arthropods can reduce prey consumption depending on predator species and on likely risks associated with toxicity.

  17. Effects of Sublethal Concentrations of Insecticides on the Functional Response of Two Mirid Generalist Predators.

    Science.gov (United States)

    Martinou, Angeliki F; Stavrinides, Menelaos C

    2015-01-01

    The use of agrochemicals particularly pesticides, can hamper the effectiveness of natural enemies, causing disruption in the ecosystem service of biological control. In the current study, the effects of the insecticides thiacloprid and chlorantraniliprole on the functional response curves were assessed for two mirid predator nymphs, Macrolophus pygmaeus Rambur and Nesidiocoris tenuis Reuter. In the absence of insecticides, both predators exhibited a type II functional response when feeding on eggs of the moth Ephestia kuehniella. N. tenuis seems to be a more efficient predator than M. pygmaeus, as model estimated handling time was significantly lower for the former than for the latter. Residual exposure of M. pygmaeus to sublethal concentrations of either insecticide was associated with a change in the asymptote but not the type of the functional response curve. Thiacloprid seems to be the least compatible with M. pygmaeus, as it led to both a significant reduction of the attack rate and an increase in handling time. In contrast, chlorantraniliprole exposure significantly increased the handling time, but not the attack rate of the predator. Residual exposure of N. tenuis to sublethal concentrations of either insecticide did not have a significant effect on the type nor the parameters of the functional response model. The results show that pesticide residues that do not have lethal effects on beneficial arthropods can reduce prey consumption depending on predator species and on likely risks associated with toxicity.

  18. Sublethal and hormesis effects of imidacloprid on the soybean aphid Aphis glycines.

    Science.gov (United States)

    Qu, Yanyan; Xiao, Da; Li, Jinyu; Chen, Zhou; Biondi, Antonio; Desneux, Nicolas; Gao, Xiwu; Song, Dunlun

    2015-04-01

    The soybean aphid, Aphis glycines Matsumura, is a major pest in soybean crop. Current management of this pest relies mainly on insecticides applications, and the neonicotinoid imidacloprid has been proposed as an effective insecticide to control A. glycines in soybean field. Imidacloprid at lethal concentrations not only exerts acute toxicity to A. glycines, but also cause various biological changes when aphids are chronically exposed to lower concentrations. In this study, we assessed the effects of a low-lethal (0.20 mg L(-1)) and two sublethal (0.05 and 0.10 mg L(-1)) imidacloprid concentrations on various A. glycines life history traits. Aphid exposure to 0.20 mg L(-1) imidacloprid caused slower juvenile development, shorter reproductive period, and reduced adult longevity, fecundity and total lifespan. Stimulatory effects, i.e. hormesis, on reproduction and immature development duration were observed in aphids exposed to the lower sublethal imidacloprid concentrations. Consequently, the net reproduction rate (R 0) was significantly higher than in the control aphids. These findings stress the importance of the actual imidacloprid concentration in its toxicological properties on A. glycines. Therefore, our results would be useful for assessing the overall effects of imidacloprid on A. glycines and for optimizing integrated pest management programs targeting this pest.

  19. Lethal and sublethal effects of four essential oils on the egg parasitoids Trissolcus basalis.

    Science.gov (United States)

    Werdin González, Jorge Omar; Laumann, Raúl Alberto; da Silveira, Samantha; Moraes, Maria Carolina Blassioli; Borges, Miguel; Ferrero, Adriana Alicia

    2013-07-01

    The essential oils from leaves of Schinus molle var. areira, Aloysia citriodora, Origanum vulgare and Thymus vulgaris have showed potential as phytoinsecticides against the green stink bug, Nezara viridula. In this work were evaluated their toxicological and behavioral effects on the parasitoid Trissolcus basalis, a biological control agent of this pest insect. Essential oils were obtained via hydrodestillation from fresh leaves. Insecticide activity in T. basalis females was evaluated in direct contact and fumigation bioassays. Behavioral effects were evaluated in olfactometer bioassays. To evaluate the residual toxicity, females of the parasitoids were exposed to oil residues; in these insects, the sublethal effects were evaluated (potential parasitism and survivorship of immature stages). The essential oils from O. vulgare and T. vulgaris proved to be highly selective when used as fumigant and did not change parasitoid behavior. After one week, the residues of these oils were harmless and did not show sublethal effects against T. basalis. According with these results, essential oils have potential applications for the integrated management of N. viridula. Published by Elsevier Ltd.

  20. Effects Of Exposure To Sublethal Concentrations Of Azadirachta ...

    African Journals Online (AJOL)

    The physiological impairment on the fingerlings of Clarias gariepinus when exposed to sublethal concentrations of Azadirachta Indica was investigated. The fish were exposed to concentrations of 1.25, 2.50, 5.0, 10.0, 20.0 ML -1 for the period of 12 weeks. The crude protein content decreased with increased concentration ...

  1. Sublethal effects of carbaryl on embryonic and gonadal ...

    African Journals Online (AJOL)

    Carbaryl is a broad-spectrum insecticide used to control insect pests. In aquatic environments, it can disrupt the endocrine system and adversely affect the reproductive function of aquatic animals. This study investigated sublethal impacts of carbaryl on embryos and gonads of zebrafish Danio rerio in order to assess the ...

  2. Toxicity, sublethal effects, and potential modes of action of select fungicides on freshwater fish and invertebrates

    Science.gov (United States)

    Elskus, Adria A.

    2012-01-01

    Despite decades of agricultural and urban use of fungicides and widespread detection of these pesticides in surface waters, relatively few data are available on the effects of fungicides on fish and invertebrates in the aquatic environment. Nine fungicides are reviewed in this report: azoxystrobin, boscalid, chlorothalonil, fludioxonil, myclobutanil, fenarimol, pyraclostrobin, pyrimethanil, and zoxamide. These fungicides were identified as emerging chemicals of concern because of their high or increasing global use rates, detection frequency in surface waters, or likely persistence in the environment. A review of the literature revealed significant sublethal effects of fungicides on fish, aquatic invertebrates, and ecosystems, including zooplankton and fish reproduction, fish immune function, zooplankton community composition, metabolic enzymes, and ecosystem processes, such as leaf decomposition in streams, among other biological effects. Some of these effects can occur at fungicide concentrations well below single-species acute lethality values (48- or 96-hour concentration that effects a response in 50 percent of the organisms, that is, effective concentration killing 50 percent of the organisms in 48 or 96 hours) and chronic sublethal values (for example, 21-day no observed adverse effects concentration), indicating that single-species toxicity values may dramatically underestimate the toxic potency of some fungicides. Fungicide modes of toxic action in fungi can sometimes reflect the biochemical and (or) physiological effects of fungicides observed in vertebrates and invertebrates; however, far more studies are needed to explore the potential to predict effects in nontarget organisms based on specific fungicide modes of toxic action. Fungicides can also have additive and (or) synergistic effects when used with other fungicides and insecticides, highlighting the need to study pesticide mixtures that occur in surface waters. For fungicides that partition to

  3. Lethal and sublethal effects of imidacloprid on Osmia lignaria and clothianidin on Megachile rotundata (Hymenoptera: Megachilidae).

    Science.gov (United States)

    Abbott, V A; Nadeau, J L; Higo, H A; Winston, M L

    2008-06-01

    We examined lethal and sublethal effects of imidacloprid on Osmia lignaria (Cresson) and clothianidin on Megachile rotundata (F.) (Hymenoptera: Megachilidae). We also made progress toward developing reliable methodology for testing pesticides on wild bees for use in pesticide registration by using field and laboratory experiments. Bee larvae were exposed to control, low (3 or 6 ppb), intermediate (30 ppb), or high (300 ppb) doses of either imidacloprid or clothianidin in pollen. Field experiments on both bee species involved injecting the pollen provisions with the corresponding pesticide. Only O. lignaria was used for the laboratory experiments, which entailed both injecting the bee's own pollen provisions and replacing the pollen provision with a preblended pollen mixture containing imidacloprid. Larval development, emergence, weight, and mortality were monitored and analyzed. There were no lethal effects found for either imidacloprid or clothianidin on O. lignaria and M. rotundata. Minor sublethal effects were detected on larval development for O. lignaria, with greater developmental time at the intermediate (30 ppb) and high doses (300 ppb) of imidacloprid. No similar sublethal effects were found with clothianidin on M. rotundata. We were successful in creating methodology for pesticide testing on O. lignaria and M. rotundata; however, these methods can be improved upon to create a more robust test. We also identified several parameters and developmental stages for observing sublethal effects. The detection of sublethal effects demonstrates the importance of testing new pesticides on wild pollinators before registration.

  4. Do biopesticides affect the demographic traits of a parasitoid wasp and its biocontrol services through sublethal effects?

    Directory of Open Access Journals (Sweden)

    Antonio Biondi

    Full Text Available Pesticide risk assessments are usually based on short-term acute toxicity tests, while longer-term population dynamic related traits, critical to the success of biological control and Integrated Pest Management (IPM programs, are often overlooked. This is increasingly important with respect to new biopesticides that frequently cause no short-term acute effects, but that can induce multiple physiological and behavioral sublethal effects, leading to a decrease in population growth and ecosystem services. In this study we assessed the lethal and sublethal effects of six biopesticides [abamectin, azadirachtin, Bacillus thuringiensis, borax plus citrus oil (Prev-Am®, emamectin benzoate, and spinosad], used in tomato crops to control the invasive pest Tuta absoluta (Lepidoptera: Gelechiidae, on adults and pupae of the parasitoid Bracon nigricans (Hymenoptera: Braconidae. Data on female survival and production of female offspring were used to calculate population growth indexes as a measure of population recovery after pesticide exposure. Spinosad caused 100% and 80% mortality in exposed adults (even 10 d after the treatment and pupae, respectively. Although most of the biopesticides had low levels of acute toxicity, multiple sublethal effects were observed. The biocontrol activity of both females that survived 1-h and 10-d old residues, and females that emerged from topically treated pupae was significantly affected by the application of the neurotoxic insecticides emamectin benzoate and abamectin. Furthermore, very low B. nigricans demographic growth indices were estimated for these two insecticides, indicating potential local extinction of the wasp populations. Among the tested products, Bt proved to be the safest for B. nigricans adults and pupae. Our findings emphasize that acute toxicity assessment alone cannot fully predict the actual impact of pesticides on non-target parasitoids. Thus, sublethal effects related to the species specific life

  5. Do Biopesticides Affect the Demographic Traits of a Parasitoid Wasp and Its Biocontrol Services through Sublethal Effects?

    Science.gov (United States)

    Biondi, Antonio; Zappalà, Lucia; Stark, John D.; Desneux, Nicolas

    2013-01-01

    Pesticide risk assessments are usually based on short-term acute toxicity tests, while longer-term population dynamic related traits, critical to the success of biological control and Integrated Pest Management (IPM) programs, are often overlooked. This is increasingly important with respect to new biopesticides that frequently cause no short-term acute effects, but that can induce multiple physiological and behavioral sublethal effects, leading to a decrease in population growth and ecosystem services. In this study we assessed the lethal and sublethal effects of six biopesticides [abamectin, azadirachtin, Bacillus thuringiensis, borax plus citrus oil (Prev-Am®), emamectin benzoate, and spinosad], used in tomato crops to control the invasive pest Tuta absoluta (Lepidoptera: Gelechiidae), on adults and pupae of the parasitoid Bracon nigricans (Hymenoptera: Braconidae). Data on female survival and production of female offspring were used to calculate population growth indexes as a measure of population recovery after pesticide exposure. Spinosad caused 100% and 80% mortality in exposed adults (even 10 d after the treatment) and pupae, respectively. Although most of the biopesticides had low levels of acute toxicity, multiple sublethal effects were observed. The biocontrol activity of both females that survived 1-h and 10-d old residues, and females that emerged from topically treated pupae was significantly affected by the application of the neurotoxic insecticides emamectin benzoate and abamectin. Furthermore, very low B. nigricans demographic growth indices were estimated for these two insecticides, indicating potential local extinction of the wasp populations. Among the tested products, Bt proved to be the safest for B. nigricans adults and pupae. Our findings emphasize that acute toxicity assessment alone cannot fully predict the actual impact of pesticides on non-target parasitoids. Thus, sublethal effects related to the species specific life-history variables

  6. Investigation of ionizing sublethal doses effects on endogenous radioresistance background

    International Nuclear Information System (INIS)

    Kudryashov, Yu.B.; Goncharenko, E.N.; Antonova, S.V.; Akhalaya, M.Ya.; Bajzhumanov, A.A.; Shestakova, S.V.

    1997-01-01

    Sublethal doses of X-radiation (0.5 Gy and 1 Gy) caused the alterations in levels of main components of endogenous radioresistance background in rat tissues. There were demonstrated the decrease of serotonin content in stomach mocosa and spleen, adrenalin, noradrenalin and corticosteroids contents in adrenal glands, nonprotein thiols content in spleen and the increase of lipid peroxide level in serum on the 3-14 days after irradiation. The recovery of the investigated parameters was occurred to the 21 day after exposure. (author)

  7. Acute toxicity and sublethal effects of gallic and pelargonic acids on the zebrafish Danio rerio.

    Science.gov (United States)

    Techer, Didier; Milla, Sylvain; Fontaine, Pascal; Viot, Sandrine; Thomas, Marielle

    2015-04-01

    Gallic and pelargonic acids are naturally found in a variety of plants and food products. Despite their extensive use in man-made applications, little is known regarding their potential risks to aquatic vertebrates. The aim of this work was to assess the acute toxicity of these polyphenolic and fatty acid compounds to the zebrafish. In order to get insights into sublethal effects, the enzyme activity of usual biomarkers related to oxidative stress and biotransformation were also assessed in fish. These latter included total superoxide dismutase, catalase as well as total glutathione peroxidase for antioxidant defence mechanisms and glutathione S-transferase for biotransformation related enzyme. Gallic acid was practically non-toxic (96-h lethal concentration (LC50) > 100 mg/L) whereas pelargonic acid was slightly toxic (96-h LC50 of 81.2 mg/L). Moreover, biomarker analyses indicated enhanced superoxide dismutase activity in fish exposed to 20, 40 and 100 mg/L of gallic acid compared to control. A dose-dependent induction of glutathione peroxidase and glutathione S-transferase was reported following gallic acid exposure at the tested concentrations of 10, 20 and 40 mg/L, with the exception of 100 mg/L of substance where basal activity levels were reported. In the case of pelargonic acid, there was no change in antioxidant enzyme activity while an inhibition of glutathione S-transferase was observed from organisms exposed to 45, 58 and 76 mg/L of test solution. The results concerning sublethal effects on biological parameters of zebrafish highlighted thereby the need for further investigations following chronic exposure to both organic acids.

  8. Monitoring colony-level effects of sublethal pesticide exposure on honey bees

    Science.gov (United States)

    The effects of sublethal pesticide exposure to honey bee colonies may be significant but difficult to detect in the field using standard visual assessment methods. Here we describe methods to measure the quantities of adult bees, brood and food resources by weighing hives and hive parts, by photogra...

  9. Effect of sublethal preculturing on the survival of probiotics and metabolite formation in set-yoghurt

    NARCIS (Netherlands)

    Settachaimongkon, S.; Valenberg, van H.J.F.; Winata, V.; Wang, X.; Nout, M.J.R.; Hooijdonk, van A.C.M.; Zwietering, M.H.; Smid, E.J.

    2015-01-01

    The objective of this study was to investigate the effect of preculturing of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB12 under sublethal stress conditions on their survival and metabolite formation in set-yoghurt. Prior to co-cultivation with yoghurt starters in milk,

  10. Assessment of chronic sublethal effects of imidacloprid on honey bee colony health

    Science.gov (United States)

    Here we present results of a three-year study to determine the fate of imidacloprid residues in hive matrices and to assess chronic sublethal effects on whole honey bee colonies fed supplemental pollen diet containing imidacloprid at 5, 20 and 100 µg/kg over multiple brood cycles. Various endpoints ...

  11. Sub-lethal effects of neonicitinoids on the alfalfa leafcutter bee, Megachile rotundata

    Science.gov (United States)

    Neonicotinoids are commonly used pesticides in U.S. agriculture. For many beneficial insect species, lethal effects of neonicotinoids are well-documented; however, much less is known about sublethal exposure. The alfalfa leaf cutter bee Megachile rotundata is a managed pollinator that constructs com...

  12. Effects of sublethal concentrations of formalin on weight gain in the ...

    African Journals Online (AJOL)

    The African Catfish, Clarias gariepinus, was exposed to various sublethal concentrations (25.0, 12.50, 6.25, 3.125, 1.56 and 0.0 mgl-1) of formalin to investigate their effects on the weight gain of the fish. Decrease in weight gain, directly proportional to the toxicant concentration, was observed in fish exposed to ...

  13. RFID Tracking of Sublethal Effects of Two Neonicotinoid Insecticides on the Foraging Behavior of Apis mellifera

    Science.gov (United States)

    Schneider, Christof W.; Tautz, Jürgen; Grünewald, Bernd; Fuchs, Stefan

    2012-01-01

    The development of insecticides requires valid risk assessment procedures to avoid causing harm to beneficial insects and especially to pollinators such as the honeybee Apis mellifera. In addition to testing according to current guidelines designed to detect bee mortality, tests are needed to determine possible sublethal effects interfering with the animal's vitality and behavioral performance. Several methods have been used to detect sublethal effects of different insecticides under laboratory conditions using olfactory conditioning. Furthermore, studies have been conducted on the influence insecticides have on foraging activity and homing ability which require time-consuming visual observation. We tested an experimental design using the radiofrequency identification (RFID) method to monitor the influence of sublethal doses of insecticides on individual honeybee foragers on an automated basis. With electronic readers positioned at the hive entrance and at an artificial food source, we obtained quantifiable data on honeybee foraging behavior. This enabled us to efficiently retrieve detailed information on flight parameters. We compared several groups of bees, fed simultaneously with different dosages of a tested substance. With this experimental approach we monitored the acute effects of sublethal doses of the neonicotinoids imidacloprid (0.15–6 ng/bee) and clothianidin (0.05–2 ng/bee) under field-like circumstances. At field-relevant doses for nectar and pollen no adverse effects were observed for either substance. Both substances led to a significant reduction of foraging activity and to longer foraging flights at doses of ≥0.5 ng/bee (clothianidin) and ≥1.5 ng/bee (imidacloprid) during the first three hours after treatment. This study demonstrates that the RFID-method is an effective way to record short-term alterations in foraging activity after insecticides have been administered once, orally, to individual bees. We contribute further information on

  14. RFID tracking of sublethal effects of two neonicotinoid insecticides on the foraging behavior of Apis mellifera.

    Directory of Open Access Journals (Sweden)

    Christof W Schneider

    Full Text Available The development of insecticides requires valid risk assessment procedures to avoid causing harm to beneficial insects and especially to pollinators such as the honeybee Apis mellifera. In addition to testing according to current guidelines designed to detect bee mortality, tests are needed to determine possible sublethal effects interfering with the animal's vitality and behavioral performance. Several methods have been used to detect sublethal effects of different insecticides under laboratory conditions using olfactory conditioning. Furthermore, studies have been conducted on the influence insecticides have on foraging activity and homing ability which require time-consuming visual observation. We tested an experimental design using the radiofrequency identification (RFID method to monitor the influence of sublethal doses of insecticides on individual honeybee foragers on an automated basis. With electronic readers positioned at the hive entrance and at an artificial food source, we obtained quantifiable data on honeybee foraging behavior. This enabled us to efficiently retrieve detailed information on flight parameters. We compared several groups of bees, fed simultaneously with different dosages of a tested substance. With this experimental approach we monitored the acute effects of sublethal doses of the neonicotinoids imidacloprid (0.15-6 ng/bee and clothianidin (0.05-2 ng/bee under field-like circumstances. At field-relevant doses for nectar and pollen no adverse effects were observed for either substance. Both substances led to a significant reduction of foraging activity and to longer foraging flights at doses of ≥0.5 ng/bee (clothianidin and ≥1.5 ng/bee (imidacloprid during the first three hours after treatment. This study demonstrates that the RFID-method is an effective way to record short-term alterations in foraging activity after insecticides have been administered once, orally, to individual bees. We contribute further

  15. Sublethal Effects in Pest Management: A Surrogate Species Perspective on Fruit Fly Control

    Directory of Open Access Journals (Sweden)

    John E. Banks

    2017-07-01

    Full Text Available Tephritid fruit flies are economically important orchard pests globally. While much effort has focused on controlling individual species with a combination of pesticides and biological control, less attention has been paid to managing assemblages of species. Although several tephritid species may co-occur in orchards/cultivated areas, especially in mixed-cropping schemes, their responses to pesticides may be highly variable. Furthermore, predictive efforts about toxicant effects are generally based on acute toxicity, with little or no regard to long-term population effects. Using a simple matrix model parameterized with life history data, we quantified the responses of several tephritid species to the sublethal effects of a toxicant acting on fecundity. Using a critical threshold to determine levels of fecundity reduction below which species are driven to local extinction, we determined that threshold levels vary widely for the three tephritid species. In particular, Bactrocera dorsalis was the most robust of the three species, followed by Ceratitis capitata, and then B. cucurbitae, suggesting individual species responses should be taken into account when planning for area-wide pest control. The rank-order of susceptibility contrasts with results from several field/lab studies testing the same species, suggesting that considering a combination of life history traits and individual species susceptibility is necessary for understanding population responses of species assemblages to toxicant exposure.

  16. EVALUATION OF SUBLETHAL EFFECTS OF Ipomoea cairica LINN. EXTRACT ON LIFE HISTORY TRAITS OF DENGUE VECTORS

    Directory of Open Access Journals (Sweden)

    Wan Fatma ZUHARAH

    2016-01-01

    Full Text Available Plant derived insecticides have considerable potential for mosquito control because these products are safer than conventional insecticides. This study aimed to investigate sublethal activities of Ipomoea carica or railway creeper crude acethonilic extract against life history trait of dengue vectors, Aedes albopictus and Aedes aegypti. The late third instar larvae of Ae. albopictus and Ae. aegypti were exposed to a sublethal dose at LC50 and larvae that survived were further cultured. Overall, Ipomea cairica crude extracts affected the whole life history of both Aedes species. The study demonstrated significantly lower egg production (fecundity and eggs hatchability (fertility in Ae. albopictus. The sublethal dose of crude extracts reduced significantly the width of larval head capsule and the wing length of both sexes in both Aedes species. The significance of sublethal effects of I. cairica against Aedes mosquitoes was an additional hallmark to demonstrate further activity of this plant despite its direct toxicity to the larvae. The reduced reproductive capacity as well as morphological and physiological anomalies are some of the effects that make I. cairica a potential candidate to be used as a new plant-based insecticide to control dengue vectors.

  17. Sublethal Effects of the Neonicotinoid Insecticide Thiamethoxam on the Transcriptome of the Honey Bees (Hymenoptera: Apidae).

    Science.gov (United States)

    Shi, Teng-Fei; Wang, Yu-Fei; Liu, Fang; Qi, Lei; Yu, Lin-Sheng

    2017-12-05

    Neonicotinoid insecticides are now the most widely used insecticides in the world. Previous studies have indicated that sublethal doses of neonicotinoids impair learning, memory capacity, foraging, and immunocompetence in honey bees (Apis mellifera, Linnaeus) (Hymenoptera: Apidae). Despite these, few studies have been carried out on the molecular effects of neonicotinoids. In this study, we focus on the second-generation neonicotinoid thiamethoxam, which is currently widely used in agriculture to protect crops. Using high-throughput RNA-Seq, we investigated the transcriptome profile of honey bees after subchronic exposure to 10 ppb thiamethoxam over 10 d. In total, 609 differentially expressed genes (DEGs) were identified, of which 225 were upregulated and 384 were downregulated. Several genes, including vitellogenin, CSP3, defensin-1, Mrjp1, and Cyp6as5 were selected and further validated using real-time quantitative polymerase chain reaction assays. The functions of some DEGs were identified, and Gene Ontology-enrichment analysis showed that the enriched DEGs were mainly linked to metabolism, biosynthesis, and translation. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that thiamethoxam affected biological processes including ribosomes, the oxidative phosphorylation pathway, tyrosine metabolism pathway, pentose and glucuronate interconversions, and drug metabolism. Overall, our results provide a basis for understanding the molecular mechanisms of the complex interactions between neonicotinoid insecticides and honey bees. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Radioprotective effect of chitosan in sub-lethally X-ray irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Yoshikazu; Ikota, Nobuo; Arima, Hiromi; Watanabe, Yoshito; Yukawa, Masae; Ozawa, Toshihiko [National Inst. of Radiological Sciences, Chiba (Japan); Kim, Hee-Sun [Korea Hydro and Nuclear Power Corp., Seoul (Korea, Republic of). Radiation Health Research Inst.; Bom, Hee-Seung; Kim, Young-Ho [Chonnam Univ., Kwangju (Korea, Republic of). Hospital

    2003-03-01

    The radioprotective effect of chitosan was studied in mice following whole-body X-ray irradiation. C3H/He mice were exposed to 7 Gy, and their survival rates were examined. The survival rates of chitosan-diet mice were about 20% higher than those of mice on a standard diet, and the rates dropped sharply to a plateau at day 10 after X-ray irradiation. The chitosan-diet mice had an increased weight ratio of spleen to body within the experimental period. The leukocyte, thrombocyte, and erythrocyte counts as well as the hematocrit and hemoglobin levels were recovered significantly and more rapidly in the chitosan-diet mice than the standard-diet mice at day 14 after irradiation. The scavenging abilities of chitosan were evaluated by the electron spin resonance (ESR) spin-trapping method. These observations suggested that chitosan led to hematopoetic activation and leuko-cytogenesis in mice after sub-lethal dose irradiation, and that the biological response might be caused by radical trapping or scavenging. (author)

  19. Effects of sublethal exposure to metofluthrin on the fitness of Aedes aegypti in a domestic setting in Cairns, Queensland.

    Science.gov (United States)

    Buhagiar, Tamara S; Devine, Gregor J; Ritchie, Scott A

    2017-05-31

    Metofluthrin is highly effective at reducing biting activity in Aedes aegypti. Its efficacy lies in the rapid onset of confusion, knockdown, and subsequent kill of a mosquito. In the field, there are a variety of scenarios that might result in sublethal exposure to metofluthrin, including mosquitoes that are active at the margins of the chemical's lethal range, brief exposure as mosquitoes fly in and out of treated spaces or decreasing efficacy of the emanators with time. Sublethal effects are key elements of insecticide exposure and selection. The metofluthrin dose for each treatment group of male and female Ae. aegypti was controlled using exposure time intervals to a 10% active ingredient (AI) metofluthrin emanator. Room size and distance from the emanator for all groups was maintained at 3 m. In bioassay cages, male Ae. aegypti were exposed at 0, 5, 10, 20, 30 and 40-min intervals. Females were exposed in bioassay cages at 0, 10, 20, 30, 40 and 60-min intervals. Mortality rates and fecundity were observed between the exposure time groups for both sexes. Female Ae. aegypti exposed for 60 min had a significantly higher mortality rate (50%), after a 24-h recovery period, than other exposure times, 10, 20, 30 and 40 min (P metofluthrin exposure were as likely to produce viable eggs with an unexposed female as males that had not been exposed (P > 0.05). Regardless of sex, if a mosquito survived exposure, it would be as biologically successful as its unexposed counterpart. Portability of the metofluthrin emanator and delayed knockdown effects create opportunities for sublethal exposure and potential pyrethroid resistance development in Ae. aegypti, and should be taken into consideration in recommendations for field application of this product, including minimum exposure periods and a prescribed number of emanators per room based on volume.

  20. Chronic Sublethal Effects of Cantharidin on the Diamondback Moth Plutella xylostella (Lepidoptera: Plutellidae

    Directory of Open Access Journals (Sweden)

    Zhengyu Huang

    2015-05-01

    Full Text Available The diamondback moth, Plutella xylostella (Linnaeus (Lepidoptera: Plutellidae, is a major pest of cruciferous vegetables worldwide. Cantharidin, a natural toxin isolated from blister beetles, has been reported to be toxic to P. xylostella. However, little is known on the chronic sublethal effects of cantharidin on this species. In this study, we assessed the changes of susceptibility, development, reproduction and other demographic parameters in both the selected P. xylostella strain (Sub, selected by LC25 cantharidin for consecutive 12 generations and the revertant strain (SubR, derived from the Sub strain without being exposed to cantharidin for 12 generations. Results revealed that the two strains maintained a relatively high-level susceptibility to cantharidin. Severe adverse effects on the population dynamics and fitness in Sub strain were observed. In addition, repeated exposure of P. xylostella to sublethal concentration of cantharidin resulted in negative effects on adult performance and deformities in adults. Although morphologically normal for individuals, the SubR strain exhibited a disadvantage in population growth rate. Our results showed that sublethal concentration of cantharidin exhibited severe negative effects on population growth for longtime. These findings would be useful for assessing the potential effects and risk of cantharidin on P. xylostella and for developing effective integrated pest management.

  1. Chronic Sublethal Effects of Cantharidin on the Diamondback Moth Plutella xylostella (Lepidoptera: Plutellidae).

    Science.gov (United States)

    Huang, Zhengyu; Zhang, Yalin

    2015-05-29

    The diamondback moth, Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), is a major pest of cruciferous vegetables worldwide. Cantharidin, a natural toxin isolated from blister beetles, has been reported to be toxic to P. xylostella. However, little is known on the chronic sublethal effects of cantharidin on this species. In this study, we assessed the changes of susceptibility, development, reproduction and other demographic parameters in both the selected P. xylostella strain (Sub, selected by LC25 cantharidin for consecutive 12 generations) and the revertant strain (SubR, derived from the Sub strain without being exposed to cantharidin for 12 generations). Results revealed that the two strains maintained a relatively high-level susceptibility to cantharidin. Severe adverse effects on the population dynamics and fitness in Sub strain were observed. In addition, repeated exposure of P. xylostella to sublethal concentration of cantharidin resulted in negative effects on adult performance and deformities in adults. Although morphologically normal for individuals, the SubR strain exhibited a disadvantage in population growth rate. Our results showed that sublethal concentration of cantharidin exhibited severe negative effects on population growth for longtime. These findings would be useful for assessing the potential effects and risk of cantharidin on P. xylostella and for developing effective integrated pest management.

  2. Chronic Sublethal Effects of Cantharidin on the Diamondback Moth Plutella xylostella (Lepidoptera: Plutellidae)

    Science.gov (United States)

    Huang, Zhengyu; Zhang, Yalin

    2015-01-01

    The diamondback moth, Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), is a major pest of cruciferous vegetables worldwide. Cantharidin, a natural toxin isolated from blister beetles, has been reported to be toxic to P. xylostella. However, little is known on the chronic sublethal effects of cantharidin on this species. In this study, we assessed the changes of susceptibility, development, reproduction and other demographic parameters in both the selected P. xylostella strain (Sub, selected by LC25 cantharidin for consecutive 12 generations) and the revertant strain (SubR, derived from the Sub strain without being exposed to cantharidin for 12 generations). Results revealed that the two strains maintained a relatively high-level susceptibility to cantharidin. Severe adverse effects on the population dynamics and fitness in Sub strain were observed. In addition, repeated exposure of P. xylostella to sublethal concentration of cantharidin resulted in negative effects on adult performance and deformities in adults. Although morphologically normal for individuals, the SubR strain exhibited a disadvantage in population growth rate. Our results showed that sublethal concentration of cantharidin exhibited severe negative effects on population growth for longtime. These findings would be useful for assessing the potential effects and risk of cantharidin on P. xylostella and for developing effective integrated pest management. PMID:26035491

  3. The effects of oil sands wastewater on fish resulting from exposure to sub-lethal concentrations

    International Nuclear Information System (INIS)

    Birkholz, D.A.; Goudey, J.S.; Balch, G.C.; Nelson, L.R.; MacKinnon, M.

    1995-01-01

    Rainbow trout, Oncorhynchus mykiss, were exposed to sub-lethal concentrations of oil sands wastewater in flow through laboratory experiments as well as to artificial ponds containing sub-lethal concentrations of tailings pond water and fine tails in order to study the viability of the wet landscape remediation option. Large (200--300 g) fish were used for all the exposures in this preliminary study and the following data were collected: blood cell counts, sex hormone concentrations, sexual maturation, stress protein concentrations, PAH-metabolites in bile, condition factors, liver somatic indices, mixed function oxygenase induction, PAHs in muscle, external condition and the condition of internal organs. The data obtained from this study revealed no adverse effects upon fish during extended field exposures. Given similar exposure conditions in the release waters of a wet landscape reclamation, the data suggest that there may be no adverse effects upon fish, however, longer term studies, other indicator organisms and additional chronic tests should be conducted

  4. Lethal and Sublethal Effects of Insecticides Used on Citrus, on the Ectoparasitoid Tamarixia radiata.

    Science.gov (United States)

    Beloti, Vitor Hugo; Alves, Gustavo Rodrigues; Araújo, Diogo Feliciano Dias; Picoli, Mateus Manara; Moral, Rafael de Andrade; Demétrio, Clarice Garcia Borges; Yamamoto, Pedro Takao

    2015-01-01

    Huanglongbing (HLB) is a disease associated with the bacteria "Candidatus Liberibacter spp." and has been devastating citrus orchards around the world. Its management involves control of the insect vector, the Asian citrus psyllid Diaphorina citri Kuwayama. However, the indiscriminate use of chemicals has caused pest outbreaks and eliminated the natural enemies of the vector, such as the parasitoid Tamarixia radiata (Waterston), the main agent for biological control of D. citri. This study assessed the lethal and sublethal effects of insecticides recommended for integrated production of citrus on the parasitoid T. radiata. When adult parasitoids were exposed to residues of 25 insecticides, 20% of them, i.e., gamma-cyhalothrin, etofenprox, azadirachtin, tebufenozide and pyriproxyfen, were considered as harmless (Class 1), 12% as slightly harmful (Class 2), 12% as moderately harmful (Class 3) and 56% as harmful (Class 4), according to the classification proposed by the IOBC/WPRS. Afterward, 14 insecticides (5 harmless and 9 harmful) were sprayed on the parasitoid pupae. Of the 14 insecticides tested, only the organophosphates dimethoate and chlorpyrifos affected the parasitoid emergence. The effects of insecticides on the parasitism capacity of adults exposed to residues of azadirachtin, etofenprox, gamma-cyhalothrin, pyriproxyfen and tebufenozide (harmless) were also evaluated. Tebufenozide and gamma-cyhalothrin affected the parasitism of the F0 generation, but did not affect the emergence of the F1 and F2 generations. Therefore, for an effective IPM program, selective insecticides or harmful pesticides to adult parasitoids could be used in the field, provided that the adults do not occur naturally and the chemical applications do not coincide with parasitoid releases.

  5. Lethal and Sublethal Effects of Insecticides Used on Citrus, on the Ectoparasitoid Tamarixia radiata.

    Directory of Open Access Journals (Sweden)

    Vitor Hugo Beloti

    Full Text Available Huanglongbing (HLB is a disease associated with the bacteria "Candidatus Liberibacter spp." and has been devastating citrus orchards around the world. Its management involves control of the insect vector, the Asian citrus psyllid Diaphorina citri Kuwayama. However, the indiscriminate use of chemicals has caused pest outbreaks and eliminated the natural enemies of the vector, such as the parasitoid Tamarixia radiata (Waterston, the main agent for biological control of D. citri. This study assessed the lethal and sublethal effects of insecticides recommended for integrated production of citrus on the parasitoid T. radiata. When adult parasitoids were exposed to residues of 25 insecticides, 20% of them, i.e., gamma-cyhalothrin, etofenprox, azadirachtin, tebufenozide and pyriproxyfen, were considered as harmless (Class 1, 12% as slightly harmful (Class 2, 12% as moderately harmful (Class 3 and 56% as harmful (Class 4, according to the classification proposed by the IOBC/WPRS. Afterward, 14 insecticides (5 harmless and 9 harmful were sprayed on the parasitoid pupae. Of the 14 insecticides tested, only the organophosphates dimethoate and chlorpyrifos affected the parasitoid emergence. The effects of insecticides on the parasitism capacity of adults exposed to residues of azadirachtin, etofenprox, gamma-cyhalothrin, pyriproxyfen and tebufenozide (harmless were also evaluated. Tebufenozide and gamma-cyhalothrin affected the parasitism of the F0 generation, but did not affect the emergence of the F1 and F2 generations. Therefore, for an effective IPM program, selective insecticides or harmful pesticides to adult parasitoids could be used in the field, provided that the adults do not occur naturally and the chemical applications do not coincide with parasitoid releases.

  6. Lethal and sublethal effects of azadirachtin on the bumblebee Bombus terrestris (Hymenoptera: Apidae).

    Science.gov (United States)

    Barbosa, Wagner Faria; De Meyer, Laurens; Guedes, Raul Narciso C; Smagghe, Guy

    2015-01-01

    Azadirachtin is a biorational insecticide commonly reported as selective to a range of beneficial insects. Nonetheless, only few studies have been carried out with pollinators, usually emphasizing the honeybee Apis mellifera and neglecting other important pollinator species such as the bumblebee Bombus terrestris. Here, lethal and sublethal effects of azadirachtin were studied on B. terrestris via oral exposure in the laboratory to bring out the potential risks of the compound to this important pollinator. The compound was tested at different concentrations above and below the maximum concentration that is used in the field (32 mg L(-1)). As most important results, azadirachtin repelled bumblebee workers in a concentration-dependent manner. The median repellence concentration (RC50) was estimated as 504 mg L(-1). Microcolonies chronically exposed to azadirachtin via treated sugar water during 11 weeks in the laboratory exhibited a high mortality ranging from 32 to 100 % with a range of concentrations between 3.2 and 320 mg L(-1). Moreover, no reproduction was scored when concentrations were higher than 3.2 mg L(-1). At 3.2 mg L(-1), azadirachtin significantly inhibited the egg-laying and, consequently, the production of drones during 6 weeks. Ovarian length decreased with the increase of the azadirachtin concentration. When azadirachtin was tested under an experimental setup in the laboratory where bumblebees need to forage for food, the sublethal effects were stronger as the numbers of drones were reduced already with a concentration of 0.64 mg L(-1). Besides, a negative correlation was found between the body mass of male offspring and azadirachtin concentration. In conclusion, our results as performed in the laboratory demonstrated that azadirachtin can affect B. terrestris with a range of sublethal effects. Taking into account that sublethal effects are as important as lethal effects for the development and survival of the colonies of B. terrestris

  7. Host defenses in experimental scrub typhus: effect of sublethal gamma radiation

    International Nuclear Information System (INIS)

    Kelly, D.J.

    1983-01-01

    The effect of sublethal gamma radiation on inbred mice chronically infected with scrub typhus rickettsiae was examined. Inbred mice which have been inoculated with Gilliam or Karp strain of Rickettsia tsutsugamushi by the subcutaneous route harbored the infection for at least one year. Irradiation of these animals at 12 or 52 weeks post inoculation at normally sublethal levels induced a significantly higher percentage of rickettsemic mice (recrudescence) than in the unirradiated similarly infected control animals. In addition, sublethal irradiation at 12 weeks also induced a quantitative increase in total rickettsiae. Homologous antibody titers to the rickettsiae were examined for five weeks following irradiation to determine the role of the humoral response in radiation induced recrudescence. Modification of recrudescence was investigated using radioprotective drugs. The expected results of this investigation supported the conclusion that the recrudescence of a chronic rickettsial infection in the appropriate host following immunological impairment due to battlefield or clinical exposure to gamma radiation can result in an acute, possibly lethal rickettsemia

  8. Effect of sublethal gamma radiation on host defenses in experimental scrub typhus

    International Nuclear Information System (INIS)

    Kelly, D.J.; Rees, J.C.

    1986-01-01

    The effect of sublethal gamma radiation on inbred mice chronically infected with scrub typhus rickettsiae was examined. Inbred mice which were inoculated with the Gilliam or Karp strain of Rickettsia tsutsugamushi by the subcutaneous route harbored the infection for at least 1 year. Irradiation of these animals at 12 or 52 weeks postinoculation with normally sublethal levels induced a significantly higher percentage of rickettsemic mice (recrudescence) than was seen in the unirradiated, similarly infected control animals. In addition, sublethal irradiation at 12 weeks induced a quantitative increase in total rickettsiae. Homologous antibody titers to the rickettsiae were examined for 5 weeks after irradiation to determine the role of the humoral response in radiation-induced recrudescence. Unirradiated, infected mice showed consistent titers of about 320 throughout the 5-week observation period, and the titer was not affected by exposure of up to 500 rads of gamma radiation. Drug dose-dependent radioprotection and modification of recrudescence was noted in infected, irradiated mice treated with the antiradiation compound S-2-(3-aminopropylamino)ethyl phosphorothioic acid. The results of this investigation supported the conclusion that the recrudescence of a chronic rickettsial infection in the appropriate host after immunological impairment due to gamma radiation can result in an acute, possibly lethal rickettsemia

  9. Effects of sublethal exposure to metofluthrin on the fitness of Aedes aegypti in a domestic setting in Cairns, Queensland

    OpenAIRE

    Buhagiar, Tamara S.; Devine, Gregor J.; Ritchie, Scott A.

    2017-01-01

    Background Metofluthrin is highly effective at reducing biting activity in Aedes aegypti. Its efficacy lies in the rapid onset of confusion, knockdown, and subsequent kill of a mosquito. In the field, there are a variety of scenarios that might result in sublethal exposure to metofluthrin, including mosquitoes that are active at the margins of the chemical?s lethal range, brief exposure as mosquitoes fly in and out of treated spaces or decreasing efficacy of the emanators with time. Sublethal...

  10. Resuspended contaminated sediments cause sublethal stress to oysters: A biomarker differentiates total suspended solids and contaminant effects.

    Science.gov (United States)

    Edge, Katelyn J; Dafforn, Katherine A; Simpson, Stuart L; Ringwood, Amy H; Johnston, Emma L

    2015-06-01

    Resuspended contaminated sediments represent an important route of contaminant exposure for aquatic organisms. During resuspension events, filter-feeding organisms are exposed to contaminants, in both the dissolved form (at the gills) and the particulate form (in the digestive system). In addition, these organisms must manage the physical stress associated with an increase in total suspended solids (TSS). To date, few studies have experimentally compared the contributions to biological stress of contaminated and clean suspended solids. The authors mixed field-collected sediments (cellular biomarkers (lysosomal membrane stability, lipid peroxidation, and glutathione) were measured to evaluate sublethal toxicity. Lysosomal membrane stability was the most sensitive biomarker for distinguishing effects from resuspended contaminated sediments, as increasing amounts of contaminated TSS increased lysosomal membrane destabilization. The authors' results illustrate the importance of considering contaminant exposures from resuspended sediments when assessing the toxicity of contaminants to aquatic organisms. © 2015 SETAC.

  11. Sublethal haematological effects of zinc on the freshwater fish ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... were taken from the control and experimental fish. ... differential white blood cell counts were decreased except for the lymphocytes in which ... this indicates a depressive effect on tissue respiration ..... the reduction in cellular blood iron, resulting in reduced ... Changes in carbohydrate metabolism occur in.

  12. Lethal and Sublethal Effects of Mineral Oil on Potato Pests.

    Science.gov (United States)

    Galimberti, Andrew; Alyokhin, Andrei

    2018-05-28

    Mineral oil is a product used to reduce Potato Virus Y transmission in potato fields. However, there is little information available about other effects that oil may have on insect pests of potato. To better understand how mineral oil affects potato pests, we performed a series of experiments testing the effects of oil on mortality, behavior, and development of potato aphids, Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae), green peach aphids, Myzus persicae (Sulzer) (Hemiptera: Aphididae), and Colorado potato beetles, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae). All three species showed negative behavioral responses to oil-treated potato foliage. Oil treatment also increased aphid mortality. Colorado potato beetle mortality was not affected, but developing on oil-treated potato plants resulted in prolonged development and smaller adults. Additionally, oil acted synergistically with the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae); Colorado potato beetle larvae were killed more rapidly when sprayed with both products compared with when sprayed with B. bassiana alone. Based on these results, mineral oil has the potential for expanded use in potato IPM programs.

  13. [Sublethal effects of spinetoram and azadirachtin on development and reproduction of Frankliniella occidentalis (Pergande).

    Science.gov (United States)

    Yang, Guang Ming; Zhi, Jun Rui; Li, Shun Xin; Liu, Li

    2016-11-18

    To evaluate the sublethal effects of spinetoram and azadirachtin on western flower thrips, Frankliniella occidentalis, leaf dipping method was used to determine their sublethal concentrations (LC 25 ) on the 2 nd instar nymph, and their influences on development and reproduction of F. occidentalis were studied. The results showed exposure of sublethal concentrations of spinetoram and azadirachtin to F. accidentalis had different degrees of effects on this insect pest. Under bisexual reproduction, the LC 25 spinetoram had no significant influences on pre-oviposition period, female adult longevity and fecundity, but male adult longevity was significantly shorter than the control. The LC 25 azadirachtin significantly reduced fecundity and prolonged pre-oviposition period. Under parthenogenesis, the LC 25 spinetoram and azadirachtin extended the pre-oviposition duration, whereas the LC 25 azadirachtin shortened the female adult longevity and significantly decreased fecundity. The LC 25 spinetoram and azadirachtin had different influences on developmental duration of each stage of next generation. The immature stage in treatment group of the LC 25 spinetoram was shorter than that in treatment group of the LC 25 azadirachtin, under bisexual reproduction or parthenogenesis. Intrinsic rate of increase (r m ) and finite rate of increase (λ) of population treated by the LC 25 spinetoram were higher than those of the control, whereas the r m , R 0 , and λ of population treated by the LC 25 azadirachtin were lower than those of the control. The findings indicated that the effects of the LC 25 spinetoram and azadirachtin on the development and reproduction of F. accidentalis were different. The LC 25 spinetoram had certain stimulating effect, whereas the LC 25 azadirach-tinon had significant inhibitory effect. Two biopesticides' influences were related with the reproductive patterns of F. accidentalis.

  14. Sublethal effects of cadmium ingestion on mallard ducks. [Anas platyrhynchos

    Energy Technology Data Exchange (ETDEWEB)

    Di Giulio, R T; Scanlon, P F

    1984-11-01

    Juvenile mallard (Anas platyrhynchos) drakes were fed diets containing 0, 50, 150, or 450 ppM cadmium for 42 +/- 1 days in order to assess the impacts of cadmium ingestion on energy metabolism and tissue metal concentrations in this species. Most significant effects on energy metabolism were observed only in the 450 ppM group which displayed reduced body and liver weights, increased kidney weights, reduced liver aldolase activity, increased plasma concentrations of uric acid, decreased plasma triiodothyronine concentrations, and elevated adrenal weights and adrenal corticosterone concentrations. Ducks in the 150 ppM group displayed increased adrenal and kidney weights and elevated plasma nonesterified fatty acid concentrations. Among all treatments, increased cadmium and zinc concentrations in both livers and kidneys were dose-related; a similar trend was observed for copper concentrations in kidneys but not livers. Cadmium interference with carbohydrate metabolism in similar studies with mammals was more severe than that observed in mallards in the present study. 52 references, 6 tables.

  15. Sublethal effects of heavy metals on biochemical composition and their recovery in Indian major carps

    International Nuclear Information System (INIS)

    Garg, Smita; Gupta, R.K.; Jain, K.L.

    2009-01-01

    Studies were conducted to assess the effects of sublethal exposure of heavy metals cadmium, arsenic and zinc for 45 days on Indian major carps, Labeo rohita, Cirrhinus mrigala and Catla catla. Heavy metal treatments in general showed significant reduction in carbohydrate and lipid contents content in muscles as well as in gills in all the three fish species. The order of reduction of muscle and gill carbohydrate and lipid content due to different treatments was Cd + As + Zn > Cd + As > As + Zn > Cd + Zn > Cd > As > Zn. When fish were transferred to metal free water for 30 days, the level of carbohydrate and lipid contents improved considerably in all the three fish species

  16. Acute toxicities and sublethal effects of some conventional insecticides on Trichogramma chilonis (Hymenoptera: Trichogrammatidae).

    Science.gov (United States)

    Wang, De-Sen; He, Yu-Rong; Guo, Xiang-Ling; Luo, Yong-Li

    2012-08-01

    The acute toxicity of 10 conventional insecticides to adult of Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae) was bioassayed by membrane method, and then their sublethal effects on the parasitoid were evaluated in the laboratory. Based on sublethal concentration (LC30) values at 8 h after treatment, we determined that adult T. chilonis were the most susceptible to chlorfenapyr, followed by fipronil, spinosad, avermectins, beta-cypermethrin, and cartap, with lethal concentration (LC)30 values of 0.3133, 0.3269, 1.5408, 3.2961, 6.1469, and 9.021 mg/liter, respectively. The field-recommended concentrations of chlorfluazuron, indoxacarb, Bacillus thuringiensis, and tebufenozide caused Cartap and spinosad also reduced longevity (8 and 7.9 d) and fecundity (110.77 and 117.2) of treated adults, but cartap enhanced the female percentage of F1 offspring (61.6%), resulting a statistical higher R0, r(m), and lambda of treated T. chilonis. In contrast, chlorfluazuron and tebufenozide increased longevity (16.4 and 15.4 d) and fecundity (248 and 256.9) of treated adults but slightly decreased the female percentage of F1 offspring (31.4 and 38.1%). Although chlorfenapyr showed no adverse influence on longevity and fecundity, it remarkably reduced the female percentage of F1 offspring (13.5%), leading to a lower R0, r(m), and lambda of treated T. chilonis. Indoxacarb, B. thuringiensis, and beta-cypermethrin had no obvious sublethal effects on the longevity and fecundity of treated adults. Based on these results, we consider B. thuringienesis, chlorfluazuron, indoxacarb, beta-cypermethrin, and tebufenozide safe to T. chilonis, suggesting that these insecticides are compatible with this parasitoid when being used in the field. However, fipronil, chlorfenapyr, spinosad, and avermectins were very harmful to T. chilonis. Timing of application of these insecticides was critical.

  17. Histological examination of sublethal effects of diazinon on ovary of bluegill, Lepomis macrochirus

    International Nuclear Information System (INIS)

    Dutta, H.M.; Maxwell, L.B.

    2003-01-01

    Sublethal doses of diazinon can alter microscopic anatomy of fish ovary. - The effects of the insecticide, diazinon (an organophosphorous compound), on the ovaries of bluegill (Lepomis macrohirus) were studied. Histological preparations of bluegill ovarian tissue was examined at 24, 48, 72 and 96 h and 1, 2 and 3 weeks following exposure to sublethal doses of diazinon (60 μg/l). The control contained primary follicles with an intact ovigerous lamellae and tunica albuginea. The control also revealed well developed stage IV oocytes with properly distributed provitelline nucleoli. After 24 h of exposure to diazinon, primary follicles began to show adhesion and cytoplasmic retraction in oocyte II occured. Cytoplasmic degeneration and additional adhesion and more retraction were visible at 48 h in oocyte II; 72 h brought forth adhesion, retraction and cytoplamic expulsion from oocyte IV. The number of atretic oocytes increased. Damages to the oocyte IV started to occur after 72 h of exposure. Cytoplasmic retraction and clumping was more visible at 96 h in oocyte IV. Partial destruction of the ovigerous lamellae and vitellogenic membrane occurred after 1 week. Two weeks continued to reveal destruction of follicles. Severe damage of the ovigerous lamellae, increased intrafollicular spaces, vacuolated cytoplasm, extrusion of karyoplasm and necrosis in the cytoplasm were most evident following 3 weeks of exposure. The ovarian wall became frayed and broken. Additionally, a marked increase of atretic follicles, shrinkage, and embedded nucleoli into the surrounding cytoplasm in oocyte II, III and IV were observed at week 3. This study revealed that oocytes at their different stages of maturation get affected differently at various exposure. Based on observations of the ovarian tissue compositional and structural changes following given exposure times, it becomes evident that consistent sublethal doses of diazinon can and will alter microscopic anatomy of the fish ovary

  18. Histological examination of sublethal effects of diazinon on ovary of bluegill, Lepomis macrochirus

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, H.M.; Maxwell, L.B

    2003-01-01

    Sublethal doses of diazinon can alter microscopic anatomy of fish ovary. - The effects of the insecticide, diazinon (an organophosphorous compound), on the ovaries of bluegill (Lepomis macrohirus) were studied. Histological preparations of bluegill ovarian tissue was examined at 24, 48, 72 and 96 h and 1, 2 and 3 weeks following exposure to sublethal doses of diazinon (60 {mu}g/l). The control contained primary follicles with an intact ovigerous lamellae and tunica albuginea. The control also revealed well developed stage IV oocytes with properly distributed provitelline nucleoli. After 24 h of exposure to diazinon, primary follicles began to show adhesion and cytoplasmic retraction in oocyte II occured. Cytoplasmic degeneration and additional adhesion and more retraction were visible at 48 h in oocyte II; 72 h brought forth adhesion, retraction and cytoplamic expulsion from oocyte IV. The number of atretic oocytes increased. Damages to the oocyte IV started to occur after 72 h of exposure. Cytoplasmic retraction and clumping was more visible at 96 h in oocyte IV. Partial destruction of the ovigerous lamellae and vitellogenic membrane occurred after 1 week. Two weeks continued to reveal destruction of follicles. Severe damage of the ovigerous lamellae, increased intrafollicular spaces, vacuolated cytoplasm, extrusion of karyoplasm and necrosis in the cytoplasm were most evident following 3 weeks of exposure. The ovarian wall became frayed and broken. Additionally, a marked increase of atretic follicles, shrinkage, and embedded nucleoli into the surrounding cytoplasm in oocyte II, III and IV were observed at week 3. This study revealed that oocytes at their different stages of maturation get affected differently at various exposure. Based on observations of the ovarian tissue compositional and structural changes following given exposure times, it becomes evident that consistent sublethal doses of diazinon can and will alter microscopic anatomy of the fish ovary.

  19. The suppressive effect of etoposide on recovery from sublethal radiation damage in Chinese hamster V 79 cells

    International Nuclear Information System (INIS)

    Saito, Tsutomu; Shimada, Yuji; Kawamori, Jiro; Kamata, Rikisaburo

    1992-01-01

    The combined effect of radiation and etoposide on the survival of cultured Chinese hamster V 79 cells was investigated. Cells in exponential growth phase were treated with various combinations of radiation and etoposide. The surviving fraction was assessed by colony formation. Etoposide significantly reduced so-called shoulder width, as expressed in Dq (quasithreshold dose), of radiation survival curves. The reduction depended on the increase of etoposide concentrations, although steepening of slopes of exponentially regressing portions of the radiation survival curves was slight. Split dose experiments showed that cells did not recover from sublethal radiation damage in the presence of low concentration of etoposide, although they did recover from sublethal radiation damage under a drug free condition. The results show the suppressive effect of etoposide on recovery from sublethal radiation damage. The effect of a sequential combination of radiation and etoposide was also investigated. The effect was more marked when the interval between radiation and etoposide was shorter regardless of the sequence. (author)

  20. Sublethal effects of spirodiclofen, abamectin and pyridaben on life-history traits and life-table parameters of two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae).

    Science.gov (United States)

    Saber, Moosa; Ahmadi, Zeinab; Mahdavinia, Gholamreza

    2018-05-01

    Two-spotted spider mite, Tetranychus urticae Koch, is one of the economically most important pests on a wide range of crops in greenhouses and orchards worldwide. Control of T. urticae has been largely based on the use of acaricides. Sublethal effects of spirodiclofen, pyridaben and abamectin were studied on life-table parameters of T. urticae females treated with the acaricides. LC 25 values of spirodiclofen, abamectin and pyridaben (3.84, 0.04 and 136.96 µg a.i./ml, respectively) were used for sublethal studies. All acaricides showed significant effects on T. urticae biological parameters including developmental time, survival rate, and fecundity. The females treated with spirodiclofen, abamectin and pyridaben at LC 25 exhibited significantly reduced net reproductive rate (R 0 ), finite rate of increase (λ) and intrinsic rate of increase (r). The intrinsic rate of increase in spirodiclofen, abamectin and pyridaben treated groups and control were 0.0138, 0.0273, 0.039 and 0.2481 female offspring per female per day, respectively. The results indicated that sublethal concentrations of tested pesticides strongly affected the life characteristics of spider mite and consequently may influence mite population growth in future generations.

  1. Biochemical and Hematological Profiles of Common Carp (Cyprinus Carpio under Sublethal Effects of Trivalent Chromium

    Directory of Open Access Journals (Sweden)

    Zeynab Abedi

    2016-07-01

    Full Text Available Background: In natural waters and/or aquaculture facilities, fish are often exposed to chromium waste and demonstrate cumulative deleterious effects. To our knowledge, there are no studies concerning the effects of trivalent Cr on C. carpio hematology. This study presents hematological and some biochemical parameters of common carp, Cyprinus carpio, affected by sublethal concentration of trivalent chromium. Methods: The fish in the experimental aquaria (three replicates each were exposed to a sublethal chromium chloride concentration of 2 mg L−1, which was prepared as stock solution and added depending on the volume of the aquaria to obtain the required concentration. After a period of 28 days, parameters such as hematocrit (Hct, hemoglobin (Hb, lymphocytes (Lym, neutrophils (Neu, total protein (TP, albumin, immunoglobulin M (IgM, glucose, red and white blood cells (RBC and WBC, mean corpuscular volume (MCV, mean corpuscular hemoglobin (MCH, and mean corpuscular hemoglobin concentration (MCHC were examined. Results: Chromium exposure for 28 days significantly (P0.05 between the Cr-exposed fish and the control. Conclusion: Hematological indices of fish, caused by chromium toxicity to C. carpio, can be secondary responses to toxicants, including exposure to low concentrations of heavy metals, which reflect the launch of stress reaction in the affected fish.

  2. Using photopigment biomarkers to quantify sub-lethal effects of petroleum pollution on natural phytoplankton assemblages

    International Nuclear Information System (INIS)

    Swistak, J.; Pinckney, J.; Piehler, M.; Paerl, H.

    1995-01-01

    Although much work has been undertaken to determine the toxicity of petroleum pollutants to phytoplankton, most studies have used pure cultures to monitor growth of selected phytoplankton species. Fewer have considered the net effect on entire microalgal communities. Using high performance liquid chromatography (HPLC) to characterize diagnostic microalgal pigments, the authors were able to simultaneously assess sub-lethal pollutant effects on entire communities as well as on individual phytoplankton functional groups. Incubations of natural water samples with diesel fuel, an important contributor to coastal petroleum pollution, revealed significant changes in photopigments and relative abundance of taxonomic groups at sub-lethal concentrations. Differential rates of change of indicator pigment concentrations suggest a range of sensitivity among phytoplankton groups. In preliminary experiments, cyanobacteria exhibited the greatest overall tolerance to the diesel fuel concentrations tested, while cryptomonads displayed the most sensitivity. The authors are currently evaluating the responses of seasonal phytoplankton populations from 3 sites exposed to varied levels of petroleum pollution. HPLC will be used to characterize phytoplankton populations and to determine if the most abundant groups are also the most tolerant of diesel fuel. Preliminary experiments indicate that diesel fuel pollution may modify the structure and function of phytoplankton communities and subsequently alter the trophodynamics of impacted systems

  3. Toxicity and sublethal effects of seven insecticides to eggs of the flower bug Orius insidiosus (Say) (Hemiptera: Anthocoridae).

    Science.gov (United States)

    Moscardini, Valéria Fonseca; Gontijo, Pablo da Costa; Carvalho, Geraldo Andrade; Oliveira, Rodrigo Lopes de; Maia, Jader Braga; Silva, Fernanda Fonseca e

    2013-07-01

    The predatory bug Orius insidiosus is an important biological control agent of several insect pests, and is one of the most commonly used species in biological control programs worldwide. This study assessed the lethal and sublethal effects of insecticides on this species through life table, and classified the insecticides according to the definitions of toxicity given by the International Organization for Biological and Integrated Control of Noxious Animals and Plants (IOBC). A bioassay was carried out using a completely randomized design with eight treatments and 40 replicates. Eggs of O. insidiosus laid naturally in plant stems were immersed in aqueous solutions of the chemical products. Egg viability, duration of the embryonic period, survival of nymphs, and duration of the nymphal period were assessed daily. Insects that reached adulthood were paired and their reproduction assessed. The number of eggs produced and the survival of adults were assessed daily. The insecticides abamectin, cartap hydrochloride, spirotetramat+imidacloprid, and flubendiamid were classified as harmful. Pyriproxyfen and rynaxypyr were categorized as harmless and pymetrozine was classified as slightly harmful. Pyriproxyfen affected the population parameters rm, GT, DT, and λ, whereas other insecticides did not. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Acute, sublethal, and combination effects of azadirachtin and Bacillus thuringiensis on the cotton bollworm, Helicoverpa armigera.

    Science.gov (United States)

    Abedi, Zahra; Saber, Moosa; Vojoudi, Samad; Mahdavi, Vahid; Parsaeyan, Ehsan

    2014-02-26

    The cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is a polyphagous and cosmopolitan insect pest that causes damage to various plants. In this study, the lethal and sublethal effects of azadirachtin and Bacillus thuringiensis Berliner sub sp . kurstaki (Bacillales: Bacillaceae) were evaluated on third instar H. armigera under laboratory conditions. The LC50 values of azadirachtin and Bt were 12.95 and 96.8 µg a.i./mL, respectively. A total mortality of 56.7% was caused on third instar larvae when LC20 values of the insecticides were applied in combination with each other. The LT50 values of azadirachtin and Bt were 4.8 and 3.6 days, respectively. The results of the sublethal study showed that the application of LC30 value of azadirachtin and Bt reduced the larval and pupal weight and increased larval and pupal duration of H. armigera. The longevity and fecundity of female adults were affected significantly by the insecticides. Female fecundity was reduced by the treatments, respectively. The lowest adult emergence ratio and pupation ratio were observed in the azadirachtin treatment. The results indicated that both insecticides have high potential for controlling of the pest. This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.

  5. The sublethal effects of the organochlorines dieldrin and lindane on growth and reproduction of Eudrilus eugeniae and Eisenia fetida (Oligochaeta

    Directory of Open Access Journals (Sweden)

    Editorial Office

    1994-07-01

    Full Text Available Experimental exposure of the earthworm species Eudrilus eugeniae to organochlorines showed that dieldrin causes damage to sperm ultrastructure when viewed electronmicroscopically. Worms containing concentrations of 7,27 mg/kg dieldrin and higher showed more than 10% sperm damage. Exposure of Eisenia fetida to sublethal concentrations of lindane did not result in sperm damage but demonstrated an increase in growth and reproductive activity. It is argued that quantification of sperm damage and correlation with pesticide concentration could provide a useful tool for evaluating environmental quality. Furthermore, the effects of sublethal concentrations of pesticides that manifest themselves in increased growth and reproductive activity could affect ecological balances.

  6. Field-level sublethal effects of approved bee hive chemicals on Honey Bees (Apis mellifera L).

    Science.gov (United States)

    Berry, Jennifer A; Hood, W Michael; Pietravalle, Stéphane; Delaplane, Keith S

    2013-01-01

    In a study replicated across two states and two years, we tested the sublethal effects on honey bees of the miticides Apistan (tau fluvalinate) and Check Mite+ (coumaphos) and the wood preservative copper naphthenate applied at label rates in field conditions. A continuous covariate, a colony Varroa mite index, helped us disambiguate the effects of the chemicals on bees while adjusting for a presumed benefit of controlling mites. Mite levels in colonies treated with Apistan or Check Mite+ were not different from levels in non-treated controls. Experimental chemicals significantly decreased 3-day brood survivorship and increased construction of queen supercedure cells compared to non-treated controls. Bees exposed to Check Mite+ as immatures had higher legacy mortality as adults relative to non-treated controls, whereas bees exposed to Apistan had improved legacy mortality relative to non-treated controls. Relative to non-treated controls, Check Mite+ increased adult emergence weight. Although there was a treatment effect on a test of associative learning, it was not possible to statistically separate the treatment means, but bees treated with Apistan performed comparatively well. And finally, there were no detected effects of bee hive chemical on colony bee population, amount of brood, amount of honey, foraging rate, time required for marked released bees to return to their nest, percentage of released bees that return to the nest, and colony Nosema spore loads. To our knowledge, this is the first study to examine sublethal effects of bee hive chemicals applied at label rates under field conditions while disambiguating the results from mite control benefits realized from the chemicals. Given the poor performance of the miticides at reducing mites and their inconsistent effects on the host, these results defend the use of bee health management practices that minimize use of exotic hive chemicals.

  7. Field-level sublethal effects of approved bee hive chemicals on Honey Bees (Apis mellifera L.

    Directory of Open Access Journals (Sweden)

    Jennifer A Berry

    Full Text Available In a study replicated across two states and two years, we tested the sublethal effects on honey bees of the miticides Apistan (tau fluvalinate and Check Mite+ (coumaphos and the wood preservative copper naphthenate applied at label rates in field conditions. A continuous covariate, a colony Varroa mite index, helped us disambiguate the effects of the chemicals on bees while adjusting for a presumed benefit of controlling mites. Mite levels in colonies treated with Apistan or Check Mite+ were not different from levels in non-treated controls. Experimental chemicals significantly decreased 3-day brood survivorship and increased construction of queen supercedure cells compared to non-treated controls. Bees exposed to Check Mite+ as immatures had higher legacy mortality as adults relative to non-treated controls, whereas bees exposed to Apistan had improved legacy mortality relative to non-treated controls. Relative to non-treated controls, Check Mite+ increased adult emergence weight. Although there was a treatment effect on a test of associative learning, it was not possible to statistically separate the treatment means, but bees treated with Apistan performed comparatively well. And finally, there were no detected effects of bee hive chemical on colony bee population, amount of brood, amount of honey, foraging rate, time required for marked released bees to return to their nest, percentage of released bees that return to the nest, and colony Nosema spore loads. To our knowledge, this is the first study to examine sublethal effects of bee hive chemicals applied at label rates under field conditions while disambiguating the results from mite control benefits realized from the chemicals. Given the poor performance of the miticides at reducing mites and their inconsistent effects on the host, these results defend the use of bee health management practices that minimize use of exotic hive chemicals.

  8. Sublethal effect of imidacloprid on Solenopsis invicta (Hymenoptera: Formicidae) feeding, digging, and foraging behavior

    Science.gov (United States)

    There is increasing evidence that exposure to neonicotinoid insecticides at sublethal levels impairs colonies of honeybee and other pollinators. Recently, it was found that sublethal contamination with neonicotinoids also affect growth and behavior of ants. In this study, we exposed red imported fi...

  9. The assessment of sublethal effects of pollutants in the sea. Review of the problems.

    Science.gov (United States)

    Waldichuk, M

    1979-08-08

    Sublethal effects of pollution may be significant to survival of a stock of marine fish or even a species. Such effects sometimes lead to reproductive failure and have been identified so far only in freshwater systems. Atlantic salmon have disappeared from many streams in Europe and eastern North America, partly as a result of pollution in their freshwater spawning areas and in their estuarine nursing grounds. Reductions in populations of marine fishes due to pollution solely have not yet been demonstrated. However, Baltic Sea seals, where reproductive failure is apparently associated with high concentrations of DDT and polychlorinated biphenyl in the blubber, may have suffered a decline owing to the presence of these organochlorines. Sublethal effects of pollutants have been studied in the laboratory, essentially under four categories: (1) physiology (growth, swimming performance, respiration, circulation); (2) biochemistry/cell structure (blood chemistry, enzyme activity, endocrinology, histochemistry); (3) behaviour/neurophysiology; and (4) reproduction. Not all pollutants elicit meaningful responses in all categories, and a response is not always linear with pollutant concentration. For application to survival of populations the response has to be ultimately related to a healthy progression through a full life cycle, including successful reproduction. In recent time, physiological studies have moved into polluted marine environments with mobile laboratories having continuous sampling capability, to observe effects of pollutants in situ on marine organisms. The Controlled Ecosystem Pollution Experiment (Cepex) in Saanich Inlet, British Columbia, endeavours to investigate the effects of low concentrations of pollutants on marine organisms in large plastic silos having a slow replacement of water.

  10. Lethal and sublethal effects of pesticides in the management of Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) on Capsicum annuum L.

    Science.gov (United States)

    Breda, Mariana O; Oliveira, José V; Esteves Filho, Alberto B; Barbosa, Douglas Rs; Santos, Andrezo A

    2017-10-01

    The evaluation of lethal and sublethal effects is of great importance for a complete assessment of the total impact of chemical compounds upon pest populations and the development of management strategies. In this study, we evaluated the lethal and sublethal effects of different synthetic and botanical products on the broad mite Polyphagotarsonemus latus (Banks), a major pest of Capsicum annuum L. and other crops. Abamectin had the highest lethal effect on P. latus, followed by spiromesifen, azadirachtin, neem oil and nitrogen fertiliser + citric acid. The sublethal effects of the products were indicated by the influence on mite population growth, affecting the numbers of females, males, larvae, pupae and eggs. Furthermore, a negative instantaneous rate of increase in P. latus and repellent effects were observed. The lethal and sublethal effects of abamectin, spiromesifen, azadirachtin and neem oil significantly affect P. latus population growth, as well as causing repellence to this mite on C. annuum, and they should be considered in the integrated pest management of this mite. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  11. Biological effects

    International Nuclear Information System (INIS)

    Trott, K.R.

    1973-01-01

    Following an introduction into the field of cellular radiation effect considering the most important experimental results, the biological significance of the colony formation ability is brought out. The inactivation concept of stem cells does not only prove to be good, according to the present results, in the interpretation of the pathogenesis of acute radiation effects on moult tissue, it also enables chronicle radiation injuries to be interpreted through changes in the fibrous part of the organs. Radiation therapy of tumours can also be explained to a large extent by the radiation effect on the unlimited reproductiveness of tumour cells. The more or less similar dose effect curves for healthy and tumour tissue in practice lead to intermittent irradiation. The dependence of the intermittent doses and intervals on factors such as Elkind recovery, synchronisation, redistribution, reoxygenation, repopulation and regeneration are reviewed. (ORU/LH) [de

  12. Sublethal effects of tritium on aquatic systems. Ecological effects of lithium and beryllium on important aquatic organisms and associted communities. Teratogenic effects of low-level magnetic fields

    International Nuclear Information System (INIS)

    Strand, J.A.; Emery, R.M.

    1980-01-01

    Continuing studies of the sublethal effects of tritium on freshwater species emphasize the potential for genetic transmission of suppressed immune competence in offspring of parental rainbow trout (Salmo gairdneri) exposed to tritium (0, 0.04, 0.4, 40.0 rads) during embryogenesis. We plan to determine the relative biological effectiveness of tritium beta irradiation when compared to 60 Co gamma irradiation using the relatively radiosensitive immune process of rainbow trout. During FY 1979, we concluded genetic effects studies and prepared a manuscript for open literature publication summarizing FY 1977 and FY 1978 studies on the permanence of suppression of the primary immune response in rainbow trout sublethally irradiated during embryogenesis. We are also studying the potential effects of beryllium and lithium on aquatic systems. Because of mining and refining subsequent to the use of these metals in the construction of fusion reactors, increased levels of each are likely to be encountered in surface waters. Studies included an evaluation of potential toxicity of lithium on embryological life stages of rainbow trout and an assessment of fate and effects in artificial stream habitats. Levels of lithium necessary to cause an observed effect would have to be at least three orders of magnitude above observed background. Studies initiated in FY 1978 include evaluation of effects of low-level magnetic fields on embryologic development of rainbow trout. The objective of these studies to provide data useful in assessing potentially harmful effects of low-level magnetic fields encountered by attendant personnel working in the transport and hot cell areas of fusion reactors. This approach is less costly than using mammalian systems, provides large numbers of experimental organisms for meaningful statistical analysis and permits examination of potential latent effects in a representative vertebrate

  13. Sub-lethal effects of Vip3A toxin on survival, development and fecundity of Heliothis virescens and Plutella xylostella.

    Science.gov (United States)

    Gulzar, Asim; Wright, Denis J

    2015-11-01

    The assessment of sub-lethal effects is important to interpret the overall insecticide efficacy in controlling insect pest populations. In addition to the lethal effect, sub-lethal effects may also occur in exposed insects. Vegetative insecticidal proteins (Vips) have shown a broad spectrum of insecticidal activity against many insect pest species. In this study the sub-lethal effects of the Bacillus thuringiensis vegetative insecticidal toxin Vip3A on the development and reproduction of Heliothis virescens F. and Plutella xylostella L. were evaluated in the laboratory. The results indicated that the sub-lethal concentration of Vip3A increased the duration of the larval and pupal stages as compared with the control treatment for both species. The percent pupation and percent adult emergence were significantly lower for Vip3A-treated insects. The proportion of pairs that produced eggs and the longevity of adults were not significantly different between treatments. H. virescens and P. xylostella treated with Vip3A showed an 11 and 17 % decrease in their intrinsic rate of increase (rm) respectively compared with untreated insects. The results from this study will be helpful to develop the strategy to incorporate Vip 3A containing crops in an integrated pest management programme.

  14. Protective effect of milk constituents and sublethal injuries limiting process effectiveness during PEF inactivation of Lb. rhamnosus.

    Science.gov (United States)

    Jaeger, H; Schulz, A; Karapetkov, N; Knorr, D

    2009-08-31

    The inactivation of Lb. rhamnosus by pulsed electric field treatment (PEF) was studied in different fractions of raw milk and Ringer solution in order to evaluate the protective effect of nutrient rich media in comparison to aqueous buffer solutions. Apart from monitoring of culturability, analysis of the physiological fitness of Lb. rhamnosus was conducted aiming to identify sublethally damaged cells. Therefore, flow cytometry and a selective medium plating technique were used and compared to each other. The goal of the study was to apply three different parameters describing the physiological fitness of the model organism Lb. rhamnosus after PEF treatment such as culturability, membrane permeability and metabolic activity depending on treatment media and parameters. A concentration dependent protective effect of the milk protein fraction could be shown and allocated to micellar casein as the major milk protein. Increasing the concentration of whey proteins up to 2% showed a similar impact on limiting the PEF inactivation of Lb. rhamnosus. The evaluation of physiological fitness of cells was based on a determination of structural and functional characteristics by rapid cellular staining using carboxyfluorescein diacetate and propidium iodide. This approach showed good accordance to the conventional selective medium plating technique for the enumeration of sublethally-injured bacteria but flow cytometry provided additional information for the characterisation of this fraction. The extent of occurrence of dead, sublethal and vital fractions of cells was found dependent on the PEF treatment parameters such as electrical field strength and energy input as well as the different milk fractions used as treatment media.

  15. Lethal and sublethal effects of azadirachtin and cypermethrin on Habrobracon hebetor (Hymenoptera: Braconidae).

    Science.gov (United States)

    Abedi, Zahra; Saber, Moosa; Gharekhani, Gholamhossein; Mehrvar, Ali; Kamita, Shizuo George

    2014-04-01

    Habrobracon hebetor Say is an ectoparasitoid of larval stage of various lepidopteran pests. Lethal and sublethal effects of azadirachtin and cypermethrin were evaluated on adult and preimaginal stages of H. hebetor under laboratory conditions. Contact exposure bioassays with adults indicated that the lethal concentration (LC50) of two commercial azadirachtin-containing formulations, NeemGuard and BioNeem, were 43.5 and 10.2 microg a.i./ml, respectively. The LC50 of cypermethrin was 5.4 microg a.i./ml. When larval stage of H. hebetor was exposed to these insecticides with a field recommended concentration of NeemGuard, BioNeem, or cypermethrin by a dip protocol, the emergence rate was reduced by 39.0, 36.6, and 97.6%, respectively. To assay the sublethal effects of these insecticides, adult wasps were exposed to an LC30 concentration of the insecticides, and then demographic parameters of the surviving wasps were determined. Fecundity, fertility, and parameters including the intrinsic rate of increase (r(m)) were affected negatively. The r(m) values following exposure to NeemGuard, BioNeem, cypermethrin, or mock treatment were 0.143, 0.149, 0.160, and 0.179, respectively, female offspring per female per day, respectively. The current study showed that cypermethrin had more acute toxicity on larval and adult stages of H. hebetor compared with azadirachin. The commercial formulations of azadirachtin and cypermethrin negatively affected most of the life table parameters of the parasitoid. Semifield and field studies are needed for obtaining more applicable results on combining H. hebetor and the tested insecticides for an integrated pest management-based strategy for crop protection.

  16. Effect of sublethal levels of ionizing radiation on a predator-prey interaction

    International Nuclear Information System (INIS)

    Chee, P.C.

    1976-01-01

    The predator-prey interaction studied was that between the largemouth bass (Micropterus salmoides) and the fathead minnow (Pimephales promelas) in an artificial test environment. Experiments were first conducted to determine the 50% lethal dose at 30 days of the minnow. Three different dose rates were used to test the effect of dose rate on the 50% lethal dose value. After the 50% lethal dose was determined the predator-prey interaction experiment was conducted using 30% of the 50% lethal dose as the highest radiation dose, this dose being considered the upper limit to sublethal radiation levels. A 4 x 4 Latin square design was chosen for the experiment, with four treatment levels (control plus three radiation levels) and four replicates. In each test 10 prey minnow were offered to one predator bass and the number of prey left after 14 days was the parameter of interest. A predator-prey interaction experiment using a single high level of radiation and two types of controls as conducted to ascertain the ability of the test environment to detect changes in the predator-prey interaction. The two types of controls were irradiated prey not exposed to predation and non-irradiated prey exposed to predation. An experiment was also conducted to test the correlation between the physical activity patterns of minnow and different doses of radiation. At a dose rate of 37.8 rad/min the 50% lethal dose at 30 days for minnow was found to be 2650 rad. It was found that dose rate had a strong influence on the 50% lethal dose. In the predator-prey interaction test it was found that the 14-day survival rate of prey was unaffected by sublethal levels of ionizing radiation. No significant correlation was detected between the physical activity patterns of minnow and radiation dose

  17. Sublethal effects of imidacloprid on targeting muscle and ribosomal protein related genes in the honey bee Apis mellifera L.

    Science.gov (United States)

    Wu, Yan-Yan; Luo, Qi-Hua; Hou, Chun-Sheng; Wang, Qiang; Dai, Ping-Li; Gao, Jing; Liu, Yong-Jun; Diao, Qing-Yun

    2017-11-21

    A sublethal concentration of imidacloprid can cause chronic toxicity in bees and can impact the behavior of honey bees. The nectar- and water-collecting, and climbing abilities of bees are crucial to the survival of the bees and the execution of responsibilities in bee colonies. Besides behavioral impact, data on the molecular mechanisms underlying the toxicity of imidacloprid, especially by the way of RNA-seq at the transcriptomic level, are limited. We treated Apis mellifera L. with sublethal concentrations of imidacloprid (0.1, 1 and 10 ppb) and determined the effect on behaviors and the transcriptomic changes. The sublethal concentrations of imidacloprid had a limited impact on the survival and syrup consumption of bees, but caused a significant increase in water consumption. Moreover, the climbing ability was significantly impaired by 10 ppb imidacloprid at 8 d. In the RNA-seq analysis, gene ontology (GO) term enrichment indicated a significant down-regulation of muscle-related genes, which might contribute to the impairment in climbing ability of bees. The enriched GO terms were attributed to the up-regulated ribosomal protein genes. Considering the ribosomal and extra-ribosomal functions of the ribosomal proteins, we hypothesized that imidacloprid also causes cell dysfunction. Our findings further enhance the understanding of imidacloprid sublethal toxicity.

  18. Effect of set up time on sublethal repair in multifield fractionated radiotherapy

    International Nuclear Information System (INIS)

    Kehwar, T.S.; Beriwal, Sushil; Sharma, S.C.

    1998-01-01

    The sublethal repair between two doses given with a variable time interval for mammalian cells in tissue culture was first demonstrated successfully by Elkind and Sutton. Subsequently on the basis of concept of sublethal damage repair between fractions, the radio therapists and radio biologists realized that dose can be increased by increasing the small size fractions. This concept is successfully being used in modern radiotherapy

  19. The effect of postirradiation application of aspartic acid salts on hemopoietic recovery in sublethally X-irradiated mice

    International Nuclear Information System (INIS)

    Pospisil, M.; Netikova, J.; Vasku, J.; Urbanek, E.

    1979-01-01

    The effect of aspartic acid salts, especially of K and Mg aspartates, on certain hematological changes in the peripheral blood and hemopoietic organs of sublethally X-irratiated male mice of the strain C57Bl/10 was investigated. Salts of aspartic acid were administered in tap water after irradiation. A favorable effect of aspartic acid salts on erythropoietic recovery and on regeneration of thymus weight was found during the first two weeks after irradiation. (orig.) [de

  20. Sublethal Effects of Neonicotinoid Insecticide on Calling Behavior and Pheromone Production of Tortricid Moths.

    Science.gov (United States)

    Navarro-Roldán, Miguel A; Gemeno, César

    2017-09-01

    In moths, sexual behavior combines female sex pheromone production and calling behavior. The normal functioning of these periodic events requires an intact nervous system. Neurotoxic insecticide residues in the agroecosystem could impact the normal functioning of pheromone communication through alteration of the nervous system. In this study we assess whether sublethal concentrations of the neonicotinoid insecticide thiacloprid, that competitively modulates nicotinic acetylcholine receptors at the dendrite, affect pheromone production and calling behavior in adults of three economically important tortricid moth pests; Cydia pomonella (L.), Grapholita molesta (Busck), and Lobesia botrana (Denis & Schiffermüller). Thiacloprid significantly reduced the amount of calling in C. pomonella females at LC 0.001 (a lethal concentration that kills only 1 in 10 5 individuals), and altered its calling period at LC 1 , and in both cases the effect was dose-dependent. In the other two species the effect was similar but started at higher LCs, and the effect was relatively small in L. botrana. Pheromone production was altered only in C. pomonella, with a reduction of the major compound, codlemone, and one minor component, starting at LC 10 . Since sex pheromones and neonicotinoids are used together in the management of these three species, our results could have implications regarding the interaction between these two pest control methods.

  1. The effect of thymus cells on bone marrow transplants into sublethally irradiated mice

    International Nuclear Information System (INIS)

    Kruszewski, J.A.; Szcylik, C.; Wiktor-Jedrzejczak, W.

    1984-01-01

    Bone marrow cells formed similar numbers of 10-days spleen colonies in sublethally (6 Gy) irradiated C57B1/6 mice as in lethally (7.5 Gy) irradiated mice i.e. approximately 20 per 10 5 cells. Numbers of 10 day endogenous spleen colonies in sublethally irradiated mice (0.2 to 0.6 per spleen) did not differ significantly from the numbers in lethally irradiated mice. Yet, transplants of 10 7 coisogenic marrow cells into sublethally irradiated mice resulted in predominantly endogenous recovery of granulocyte system as evidenced by utilization of ''beige'' marker for transplanted cells. Nevertheless, transplanted cells engrafted into sublethally irradiated mice were present in their hemopoietic tissues throughout the observation period of 2 months never exceeding 5 to 10% of cells. Thymus cells stimulated endogenous and exogenous spleen colony formation as well as endogenous granulopoietic recovery. Additionally, they increased both the frequency and absolute numbers of graft-derived granulocytic cells in hemopoietic organs of transplanted mice. They failed, however, to essentially change the quantitative relationships between endogenous and exogenous hemopoietic recovery. These results may suggest that spleen colony studies are not suitable for prediction of events following bone marrow transplant into sublethally irradiated mice. Simultaneously, they have strengthened the necessity for appropriate conditioning of recipients of marrow transplants. (orig.) [de

  2. Synergistic Effect of Combining Plutella xylostella Granulovirus and Bacillus thuringiensis at Sublethal Dosages on Controlling of Diamondback Moth (Lepidoptera: Plutellidae).

    Science.gov (United States)

    Han, Guangjie; Li, Chuanming; Liu, Qin; Xu, Jian

    2015-10-01

    Plutella xylostella granulovirus (PxGV) and Bacillus thuringiensis (Bt) are both entomo-pathogens to the diamondback moth, Plutella xylostella (L.). The purpose of the present study was to measure the effect of the combination of PxGV and Bt at sublethal dosages on the development and mortality of diamondback moth in a laboratory setting. Bt and PxGV exhibited synergistic effect on diamondback moth larval mortality and effectively controlled diamondback moth populations with low dose combination treatment. The combination of three parts per million Bt and 1.3 × 10(3) occlusion bodies per milliliter of PxGV revealed a higher larval mortality compared with the treatment of Bt or PxGV alone. Combination of Bt and PxGV at sublethal concentrations also increased larval duration, reduced oviposition and decreased adult longevity remarkably, resulting in the lowest population trend index among the treatments. The results suggested that the combination of Bt and PxGV at sublethal dosages might provide a valuable way to improve the control efficacy of diamondback moth compared with treatment of Bt or PxGV alone. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Evaluation of Pyrethrin Formulations on Dengue/Dengue Haemorrhagic Fever Vectors in the Laboratory and Sublethal Effects

    Directory of Open Access Journals (Sweden)

    S Sulaiman

    2007-12-01

    Full Text Available In Southeast Asia, Aedes aegypti (L. has been incriminated as principal vector of dengue viruses and Ae. albopictus as the secondary vector of dengue fever. Therefore, the aim of this study was to investigate the effectiveness of three for-mula¬tions of pyrethrin derived from Tanacetum cinerariaefolium against the dengue/dengue haemorrhagic fever vectors Aedes aegypti and Ae. albopictus in the laboratory. The testings employed 2 methodologies: the WHO Larval Bioassay and WHO Adult Bioassay. The results showed that all the three pyrethrin formulations had larvicidal and adulticidal activi-ties. The impact of the sublethal doses of pyrethrin formulations on Aedes spp. larvae resulted in 4-6% of alive adult emergence compared to 90% of Ae. aegypti emerging adults and 96% Ae. albopictus alive adult emergence in the control. The impact of sublethal doses of the pyrethrin formulations caused very low fecundity on both Aedes spp. compared to the control (P< 0.05.

  4. Evaluation of Pyrethrin Formulations on Dengue/Dengue Haemorrhagic Fever Vectors in the Laboratory and Sublethal Effects

    Directory of Open Access Journals (Sweden)

    S Sulaiman

    2007-11-01

    Full Text Available In Southeast Asia, Aedes aegypti (L. has been incriminated as principal vector of dengue viruses and Ae. albopictus as the secondary vector of dengue fever. Therefore, the aim of this study was to investigate the effectiveness of three for-mula¬tions of pyrethrin derived from Tanacetum cinerariaefolium against the dengue/dengue haemorrhagic fever vectors Aedes aegypti and Ae. albopictus in the laboratory. The testings employed 2 methodologies: the WHO Larval Bioassay and WHO Adult Bioassay. The results showed that all the three pyrethrin formulations had larvicidal and adulticidal activi-ties. The impact of the sublethal doses of pyrethrin formulations on Aedes spp. larvae resulted in 4-6% of alive adult emergence compared to 90% of Ae. aegypti emerging adults and 96% Ae. albopictus alive adult emergence in the control. The impact of sublethal doses of the pyrethrin formulations caused very low fecundity on both Aedes spp. compared to the control (P< 0.05.

  5. Lethal and sublethal effects of marine sediment extracts on fish cells and chromosomes

    Science.gov (United States)

    Landolt, Marsha L.; Kocan, Richard M.

    1984-03-01

    The cost of conducting conventional chronic bioassays with every potentially toxic compound found in marine ecosystems is prohibitive; therefore short-term toxicity tests which can be used for rapid screening were developed. The tests employ cultured fish cells to measure lethal, sublethal or genotoxic effects of pure compounds and complex mixtures. The sensitivity of these tests has been proven under laboratory conditions; the following study used two of these tests, the anaphase aberration test and a cytotoxicity assay, under field conditions. Sediment was collected from 97 stations within Puget Sound, Washington. Serial washings of the sediment in methanol and dichloromethane yielded an organic extract which was dried, dissolved in DMSO and incubated as a series of dilutions with rainbow trout gonad (RTG-2) cells. The toxic effects of the extract were measured by examining the rate of cell proliferation and the percentage of damaged anaphase figures. Anaphase figures were considered to be abnormal if they exhibited non-disjunctions, chromosome fragments, or chromosome bridges. A second cell line (bluegill fry, BF-2) was also tested for cell proliferation and was included because, unlike the RTG-2 cell line, it contains little or no mixed function oxygenase activity. Of 97 stations tested, 35 showed no genotoxic activity, 42 showed high genotoxic activity (P≤.01) and the remainder were intermediate. Among the toxic sites were several deep water stations adjacent to municipal sewage outfalls and four urban waterways contaminated by industrial and municipal effluents. Extracts from areas that showed genotoxic effects also inhibited cell proliferation and were cytotoxic to RTG-2 cells. Few effects were noted in the MFO deficient BF-2 cells. Short term in vitro tests provide aquatic toxicologists with a versatile and cost effective tool for screening complex environments. Through these tests one can identify compounds or geographic regions that exhibit high

  6. Sublethal effects of buprofezin on development and reproduction in the white-backed planthopper, Sogatella furcifera (Hemiptera: Delphacidae).

    Science.gov (United States)

    Ali, Ehsan; Liao, Xun; Yang, Peng; Mao, Kaikai; Zhang, Xiaolei; Shakeel, Muhammad; Salim, Abdalla M A; Wan, Hu; Li, Jianhong

    2017-12-05

    In the present study, the effects of sublethal concentrations of buprofezin on life-table traits of S. furcifera were evaluated for two consecutive generations (F0 and F1). Our results exhibited that the fecundity, life span (longevity) and hatchability of the F0 and F1 generations were significantly decreased at LC 30 compared to the control. However, copulation was not significantly affected for the F0 or F1 generations at sublethal concentrations. The female life span was affected negatively at both treatments in F0 and at LC 30 in F1, compared to the control. Furthermore, significant effects of the sublethal concentrations were found on the developmental rate of all instars except the 3 rd instar of F1. However, the pre-adult period, total pre-oviposition period (TPOP) and adult pre-oviposition period (APOP) significantly increased in F1 individuals at LC 30 and LC 10 compared to the control. Our findings revealed that demographic characters (survival rate, intrinsic rate of increase (ri), finite rate of increase (λ), net reproductive rate (R 0 ), and gross reproductive rate (GRR)) of the F1 generation (from F0 parents) significantly decreased compared to the untreated group; however, the generation time (T) increased at LC 10 . Therefore, the results suggested that buprofezin could adversely affect individuals in the successive generation.

  7. Sublethal Effects of Beauveria bassiana (Ascomycota: Hypocreales) on Life Table Parameters of Frankliniella occidentalis (Thysanoptera: Thripidae).

    Science.gov (United States)

    Zhang, Tao; Reitz, Stuart R; Wang, Haihong; Lei, Zhongren

    2015-06-01

    We assessed effects of parental exposure to Beauveria bassiana on life history traits of subsequent generations of western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). Progeny from individuals that survived fungal exposure as second instars had significantly shorter egg stages, but longer prepupal development times than corresponding untreated controls. However, survivorship to adulthood of these progeny groups did not differ. Although fecundities of the parental types did not differ, the sex ratio of progeny from fungal-treated parents was male-biased, whereas sex ratio of progeny from untreated control parents was even. We calculated life table parameters for the progeny and found that all parameters, except for generation time, were significantly less for the progeny of fungal-treated parents than for progeny of untreated parents. The intrinsic rate of increase, finite rate of increase, net reproductive rate, mean generation time, and gross reproductive rate were 0.199 d(-1), 1.229 d(-1), 21.84, 15.48 d, and 27.273, respectively, for progeny of treated thrips, and 0.266 d(-1), 1.316 d(-1), 52.540, 14.92 d, and 70.64, respectively, for progeny of control thrips. Consequently, population projections demonstrated that offspring of parents exposed to B. bassiana would increase their population more slowly than those from untreated parents. These results demonstrate that B. bassiana has sublethal effects that reduce the reproductive success of F. occidentalis and these effects should be taken into account when evaluating its use in management programs for F. occidentalis. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Lethal and sublethal effects of glyphosate (roundup active) to embryos of colombian anurans

    International Nuclear Information System (INIS)

    Triana Velasquez, Teofila Maria; Montes Rojas, Claudia; Bernal Bautista, Manuel Hernando

    2013-01-01

    Glyphosate is an herbicide widely used in agriculture, which may affect non-target species. the aim of this study was to determine the lethal (median lethal concentration - LC 5 0) and sublethal effects (changes on body size and development) of glyphosate (roundup active) to embryos of four anuran species, exposed during 96 hours under laboratory and microcosm tests. under laboratory conditions, engystomops pustulosus was the most tolerant species (LC 5 0 = 3033,18 ?g a.e./L) and rhinella marina was the most sensitive (lc50 = 1421,46 ?g a.e./L), which also showed a delayed development and significantly reduced body size. The other species had an intermediate LC50 (Rhinella humboldti = 2899.54 ?g a.e./L; hypsiboas crepitans = 2151,88 ?g a.e./L). In all cases, the laboratory LC 5 0 was lower than the concentration used in field (5392.92 ?g a.e./L), indicating a high toxic effect. In the microcosm tests, embryos of e. pustulosus were the most tolerant (LC 5 0 = 19,41 kg a.e./ha), while R. humboldti were the most sensitive (LC 5 0 = 10,61 kg a.e./ha). In this case, all four study species had a higher LC 5 0 than the concentration sprayed in field (3,69 kg a.e./ ha), so a lower lethal effect, and there were no significant differences in body size and development. This result shows that the glyphosate, as the commercial presentation roundup active, produce a moderate mortality on anuran embryos.

  9. Effect of lethal and sub-lethal concentrations of tobacco (Nicotiana ...

    African Journals Online (AJOL)

    Lethal and sub-lethal bioassays on Clarias gariepinus were conducted to evaluate the toxicity of tobacco (Nicotiana tobaccum) leaf dust on weight gain and haematological indices of Clarias gariepinus (mean weight 10.5±0.70g) in glass aquaria with aeration system. The concentrations used during the lethal exposure are: ...

  10. Sub-lethal effects of energy development on a migratory mammal—The enigma of North American pronghorn

    Directory of Open Access Journals (Sweden)

    Jon P. Beckmann

    2016-04-01

    (Pinedale Anticline Project Area [PAPA] and Jonah fields and other behavioral or ecological observations of sub-lethal effects, we failed to reject the null hypothesis that development is unrelated to parity in pronghorn biological responses. Studies intent on producing knowledge to assess whether energy development is inimical or not to ungulates will increasingly require appropriate time scales and understanding whether populations are below an expected food ceiling. Further, as with pronghorn in our study region, knowing if individuals are at the limits of their biological range (e.g. altitude where stressful winter conditions may mask impacts of development is important.

  11. Effects of sublethal exposure to lead on levels of energetic compounds in Procambarus clarkii (Girard, 1852)

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, M.; Torreblanca, A.; Del Ramo, J.; Diaz-Mayans, J. (Univ. of Valencia (Spain))

    1994-05-01

    Lead is neither essential nor beneficial to living organisms; all existing data show that its metabolic effects are adverse. Lead is toxic to all phyla of aquatic biota. Most of the lead discharged into surface water is rapidly incorporated into suspended and bottom sediments. The American red crayfish, Procambarus clarkii, lives in a wide range of environmental conditions that include highly polluted waters. Lead present in take sediments can be available to aquatic animals such as P. clarkii because it is a detritivor and burrow into the sediment. In fact, we found remarkable levels of lead in tissues of P. clarkii caught in Albufera Lake and kept 15 days in clean water (e. g. 223 [mu]g/g dry weight in gills). Furthermore, P. clarkii has a high capacity for lead accumulation from water, and gills were the most important tissue of lead accumulation. Among effects that contaminants have on the physiology of the organisms, energetic state variables are important, since they will alter both survival and reproduction. Hepatopancreas is a major site for the energetic reserve in crayfish and is a site of lead accumulation, although metal concentration in this organ is not as high as gills. The purpose of this study was to examine changes in energy reserves in hepatopancreas and gills of the crayfish P. clarkii, in response to sublethal exposure to lead. Gills are directly exposed to contaminants in the environment, and they are the first organ showing alterations by the action of the contaminants. Hepatopancreas was also chosen due to both, its relevance in the energetic metabolism and its role in heavy metal detoxification mechanisms.

  12. Acute, sublethal and combination effects of azadirachtin and Bacillus thuringiensis toxins on Helicoverpa armigera (Lepidoptera: Noctuidae) larvae.

    Science.gov (United States)

    Singh, G; Rup, P J; Koul, Opender

    2007-08-01

    The efficacy of neem (1500 ppm azadirachtin (AI)), Delfin WG, a biological insecticide based on selected strain of Bacillus thuringiensis Berliner (Bt) subspecies kurstaki, and Cry1Ac protein, either individually or in combination, were examined against first to fourth instar Helicoverpa armigera (Hübner) larvae. Using an oral administration method, various growth inhibitory concentrations (EC) and lethal concentrations (LC) were determined for each bioagent. Combinations of sublethal concentrations of Bt spray formulation with azadirachtin at EC50 or EC95 levels not only enhanced the toxicity, but also reduced the duration of action when used in a mixture. The LC20 and LC50 values for Cry1Ac toxin were 0.06 and 0.22 microg ml-1, respectively. Bt-azadirachtin combinations of LC50+EC20 and LC50+EC50 result in 100% mortality. The mortality also was significant in LC20+EC20 and LC20+EC50 mixtures. These studies imply that the combined action is not synergistic but complimentary, with azadirachtin particularly facilitating the action of Bt. The Bt spray-azadirachtin combination is more economical than combinations that involve isolating the toxic protein, as the Bt spray formulations can be combined in a spray mixture with neem. These combinations may be useful for controlling bollworm populations that have acquired resistance to Bt as they may not survive the effect of mixture. Azadirachtin may be useful as a means of reducing the endotoxin concentrations in a mixture, to promote increased economic savings and further reduce the probability of resistance development to either insect control agent.

  13. Lethal and Sub-lethal Effects of Four Insecticides on the Aphidophagous Coccinellid Adalia bipunctata (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Depalo, Laura; Lanzoni, Alberto; Masetti, Antonio; Pasqualini, Edison; Burgio, Giovanni

    2017-12-05

    Conventional insecticide assays, which measure the effects of insecticide exposure on short-term mortality, overlook important traits, including persistence of toxicity or sub-lethal effects. Therefore, such approaches are especially inadequate for prediction of the overall impact of insecticides on beneficial arthropods. In this study, the side effects of four modern insecticides (chlorantraniliprole, emamectin benzoate, spinosad, and spirotetramat) on Adalia bipunctata (L.) (Coleoptera: Coccinellidae) were evaluated under laboratory conditions by exposition on treated potted plants. In addition to investigation of acute toxicity and persistence of harmful activity in both larvae and adults of A. bipunctata, demographic parameters were evaluated, to provide a comprehensive picture of the nontarget effects of these products. Field doses of the four insecticides caused detrimental effects to A. bipunctata; but in different ways. Overall, spinosad showed the best toxicological profile among the products tested. Emamectin benzoate could be considered a low-risk insecticide, but had high persistence. Chlorantraniliprole exhibited lethal effects on early instar larvae and adults, along with a long-lasting activity, instead spirotetramat showed a low impact on larval and adult mortality and can be considered a short-lived insecticide. However, demographic analysis demonstrated that chlorantraniliprole and spirotetramat caused sub-lethal effects. Our findings highlight that sole assessment of mortality can lead to underestimation of the full impact of pesticides on nontarget insects. Demographic analysis was demonstrated to be a sensitive method for detection of the sub-lethal effects of insecticides on A. bipunctata, and this approach should be considered for evaluation of insecticide selectivity. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Effect of indomethacin, diclofenac sodium and sodium salicylate on peripheral blood cell counts in sublethally gamma-irradiated mice

    International Nuclear Information System (INIS)

    Pospisil, M.; Netikova, J.; Kozubik, A.; Pipalova, I.

    1989-01-01

    Treatment with indomethacin and diclofenac sodium was found to increase granulocyte counts in the blood of sublethally gamma-irradiated mice. Treatment with sodium salicylate was ineffective in this respect, administration of sodium salicylate together with indomethacin even decreased the indomethacin-induced effects. The results suggest that the hemopoiesis-stimulating effects of non-steroidal anti-flammatory drugs cannot be correlated with the anti-inflammatory activity but rather with the side effects of these compounds, including the action on gastro-intestinal prostanoid production. This conclusion doubts on the possibility of the usefulness of non-steroidal anti-inflammatory drugs in conditions of the radiation syndrome. (orig.) [de

  15. Biological effects of radiation

    International Nuclear Information System (INIS)

    2013-01-01

    This fourth chapter presents: cell structure and metabolism; radiation interaction with biological tissues; steps of the production of biological effect of radiation; radiosensitivity of tissues; classification of biological effects; reversibility, transmissivity and influence factors; pre-natal biological effects; biological effects in therapy and syndrome of acute irradiation

  16. Assessment of Chronic Sublethal Effects of Imidacloprid on Honey Bee Colony Health

    Science.gov (United States)

    Dively, Galen P.; Embrey, Michael S.; Kamel, Alaa; Hawthorne, David J.; Pettis, Jeffery S.

    2015-01-01

    Here we present results of a three-year study to determine the fate of imidacloprid residues in hive matrices and to assess chronic sublethal effects on whole honey bee colonies fed supplemental pollen diet containing imidacloprid at 5, 20 and 100 μg/kg over multiple brood cycles. Various endpoints of colony performance and foraging behavior were measured during and after exposure, including winter survival. Imidacloprid residues became diluted or non-detectable within colonies due to the processing of beebread and honey and the rapid metabolism of the chemical. Imidacloprid exposure doses up to 100 μg/kg had no significant effects on foraging activity or other colony performance indicators during and shortly after exposure. Diseases and pest species did not affect colony health but infestations of Varroa mites were significantly higher in exposed colonies. Honey stores indicated that exposed colonies may have avoided the contaminated food. Imidacloprid dose effects was delayed later in the summer, when colonies exposed to 20 and 100 μg/kg experienced higher rates of queen failure and broodless periods, which led to weaker colonies going into the winter. Pooled over two years, winter survival of colonies averaged 85.7, 72.4, 61.2 and 59.2% in the control, 5, 20 and 100 μg/kg treatment groups, respectively. Analysis of colony survival data showed a significant dose effect, and all contrast tests comparing survival between control and treatment groups were significant, except for colonies exposed to 5 μg/kg. Given the weight of evidence, chronic exposure to imidacloprid at the higher range of field doses (20 to 100 μg/kg) in pollen of certain treated crops could cause negative impacts on honey bee colony health and reduced overwintering success, but the most likely encountered high range of field doses relevant for seed-treated crops (5 μg/kg) had negligible effects on colony health and are unlikely a sole cause of colony declines. PMID:25786127

  17. Effect of sublethal doses of gamma radiation on DNA super helicity and survival of human fibroblasts

    International Nuclear Information System (INIS)

    Koceva-Chyla, A.

    1992-01-01

    Effect of sublethal doses of gamma radiation on cell survival and DNA super helicity in human fibroblasts was studied. Cell survival was estimated on the basis the basis of clonal growth of irradiated fibroblasts in monolayer culture in vitro. The nucleoid sedimentation technique was used to study ionizing radiation-induced DNA damage in vivo as well as to examine DNA super helicity. Increased concentrations of ethidium bromine (EB) were used to titrate the DNA super coiling response in non-irradiated cells. This response consisted of a relaxation phase (1-5 μg/ml EB) and rewinding phase (5-20 μg/ml EB). Observed biphasic dependence of sedimentation distance of nucleoid on the concentration of EB suggests the dye altered the amount of DNA super coiling in situ. The degree of DNA super coiling and thus the sedimentation rate of nucleoid in absence of EB was very sensitive to strand break induced in DNA by the doses of gamma radiation employed in the cell survival assay. Doses of 2-8 Gy of gamma radiation induced a dose -dependent reduction in the sedimentation of nucleoid. Loss of negative DNA super coiling was initially rapid (about 30% after the dose of 2 Gy) and then proceeded at a slower rate (about 35% and 48% after the doses of 4 Gy and 8 Gy respectively), indicating a significant relaxation of nucleoid structure at the doses of gamma radiation greater than 4 Gy, at which also significant decrease in fibroblasts survival occurred. Significant loss of negative DNA super coiling within the range of doses of gamma radiation resulting in significant decrease of cell survival suggests that destabilizing effect of radiation on DNA tertiary- and quaternary structures (extensive DNA breaks and relaxation of nucleonic super helicity) disturb normal functions and replications of genomic DNA, in consequence leading to a reproductive death of cells. Considering the sensitivity and simplicity of the method, the nucleoid sedimentation technique might be also a useful tool

  18. The effect of sub-lethal damage repair and exchange on the final slope of cell survival curves

    International Nuclear Information System (INIS)

    Carlone, M.C.; Wilkins, D.E.; Raaphorst, G.P.

    2003-01-01

    Full text: The Lea-Catcheside dose rate protraction factor, G, is the most widely used model to describe the effects of dose rate on cell survival. In the linear quadratic formalism, this factor modifies the beta component of cell killing; G is greatest for acute irradiations while vanishing at low dose rates. We have found a simple compartmental model that can derive the Lea-Catcheside function. This compartmental model clearly shows that the G function can only be derived using a little known assumption: the diminution of sub-lethal damage due to exchange of repairable lesions is negligible compared to that due to repair. This assumption was explicitly stated by Lea, but it does not appear to have been restated or verified since very early work on cell survival. The implication of this assumption is that sub-lethal damage can be modeled without considering exchange, which is evidenced by the fact that the G function does not contain parameters relating to exchange. By using a new model that fully accounts for repair and exchange of sublethal lesions, a cell survival expression that has a modified G function, but that retains the linear quadratic formalism, can be obtained. At low doses, this new model predicts linear-quadratic behavior, but the behavior gradually changes to mono-exponential at high doses, which is consistent with experimental observations. Modeling cell survival of well-known survival curves using the modified linear quadratic model shows statistically significant improvement in the fits to the cell survival data as compared to best fits obtained with the linear quadratic model. It is shown that these improvements in fits are due to a superior representation of the high dose region of the survival curve

  19. Gene expression of hematoregulatory cytokines is elevated endogenously after sublethal gamma irradiation and is differentially enhanced by therapeutic administration of biologic response modifiers

    International Nuclear Information System (INIS)

    Peterson, V.M.; Adamovicz, J.J.; Madonna, G.S.; Gause, W.C.; Elliott, T.B.; Moore, M.M.; Ledney, G.D.; Jackson, W.E. III

    1994-01-01

    Prompt, cytokine-mediated restoration of hematopoiesis is a prerequisite for survival after irradiation. Therapy with biologic response modifiers (BRMs), such as LPS, 3D monophosphoryl lipid A (MPL), and synthetic trehalose dicrynomycolate (S-TDCM) presumably accelerates hematopoietic recovery after irradiation are poorly defined. One hour after sublethal (7.0 Gy) 60 Co gamma irradiation, B6D2F1/J female mice received a single i.p. injection of LPS, MPL, S-TDCM, an extract from Serratia marcescens (Sm-BRM), or Tween 80 in saline (TS). Five hours later, a quantitative reverse transcription-PCR assay demonstrated marked splenic gene expression for IL-1β, IL-3, IL-6, and granulocyte-CSF (G-CSF). Enhanced gene expression for TNF-α, macrophage-CSF (M-CSF), and stem cell factor (SCF) was not detected. Injection of any BRM further enhanced cytokine gene expression and plasma levels of CSF activity within 24 h after irradiation and hastened bone marrow recovery. Mice injected with S-TDCM or Sm-BRM sustained expression of the IL-6 gene for at least 24 h after irradiation. Sm-BRM-treated mice exhibited greater gene expression for IL-1β, IL-3, TNF-α, and G-CSF at day 1 than any other BRM. When challenged with 2 LD 50/30 of Klebsiella pneumoniae 4 days after irradiation, 100% of Sm-BRM-treated mice and 70% of S-TDCM-treated mice survived, whereas ≤30% of mice treated with LPS, MPL, or TS survived. Thus, sublethal irradiation induces transient, splenic cytokine gene expression that can be differentially amplified and prolonged by BRMs. BRMs that sustained and/or enhanced irradiation-induced expression of specific cytokine genes improved survival after experimental infection. 67 refs., 7 figs., 1 tab

  20. Sublethal effects of clothianidin and Nosema spp. on the longevity and foraging activity of free flying honey bees.

    Science.gov (United States)

    Odemer, Richard; Nilles, Lisa; Linder, Nadine; Rosenkranz, Peter

    2018-03-19

    Neonicotinoids alone or in combination with pathogens are considered to be involved in the worldwide weakening of honey bees. We here present a new approach for testing sublethal and/or synergistic effects in free flying colonies. In our experiment individually marked honey bees were kept in free flying mini-hives and chronically exposed to sublethal doses of the neonicotinoid clothianidin. Additional groups of bees were challenged with Nosema infections or with combinations of the pesticide and pathogens. Longevity and flight activity of the differentially treated bees were monitored for a period of 18 days. In contrast to previous laboratory studies, no effect of the neonicotinoid treatment on mortality or flight activity could be observed. Although the lifespan of Nosema infected bees were significantly reduced compared to non-infected bees a combination of pesticide and pathogen did not reveal any synergistic effect. Our results indicate that individual bees are less impaired by neonicotinoids if kept within the social environment of the colony. The effect of such a "social buffering" should be considered in future risk assessments.

  1. Effects of chlorimuron ethyl on terrestrial and wetland plants: Levels of, and time to recovery following sublethal exposure

    International Nuclear Information System (INIS)

    Carpenter, David; Boutin, Céline; Allison, Jane E.

    2013-01-01

    Current pesticide registration guidelines call for short-term testing of plants; long-term effects on vegetative parts and reproduction remain untested. The aims of our study were to determine level of recovery and recovery times for plants exposed to the sulfonylurea herbicide chlorimuron ethyl using data collected from single species, dose–response greenhouse experiments. The nine terrestrial and eight wetland species tested showed variable levels of recovery and recovery timeframes. Many species (six terrestrial and five wetland) were vegetatively stunted at sublethal doses and were reproductively impaired. Full recovery did not occur at all doses and maximum recovery times varied from 3 to 15 weeks in this controlled environment. In a complex community, affected species may be displaced by tolerant species, through interspecific competition, before they fully recover. It is plausible that individual populations could be diminished or eliminated through reduced seedbank inputs (annuals and perennials) and asexual reproduction (perennials). - Highlights: ► Native terrestrial and wetland plants were used to assess the risks of herbicide drift. ► Vegetative and reproductive health endpoints were evaluated over time. ► Recovery rates were found to be both species and dose dependant. ► Reproductive recovery does not always equal vegetative recovery. ► Susceptible species may be displaced by resilient or resistant species. - Capsule: This study serves to bridge the gap between simplified short-term greenhouse tests and effects of herbicides on recovery of non-target plant species after sublethal exposures.

  2. Effect of sublethal exposure of Cartap on hypothalamo-neurosecretory system of the freshwater spotted murrel, Channa punctatus (Bloch).

    Science.gov (United States)

    Mishra, D K; Bohidar, K; Pandey, A K

    2008-11-01

    In order to record the effect of carbamate pesticide on hypothalamus of Channa punctatus, fish were exposed to sublethal concentration (0.18 mg l(-1), 30% LC50 for 96 hr) of Cartap for 24, 48, 72 and 96 hr under static bioassay condition. Hypothalamo-neurosecretory complex of the murrel consisted mainly of nucleus preopticus (NPO), nucleus lateralis tuberis (NLT) and their axonal tracts. NPO is a paired structure situtated on either side of the third ventricle anterodorsal to the optic chiasma and looked inverted L-shape in the sagittal section. NPO is morphologically divisible into a dorsal pars magnocellularis (PMC) consisting of large neurons and ventral pars parvocellularis (PPC) formed of smaller neurosecretory cells. NLT cells are distributed in the infundibular floor adjacent to the pituitary stalk. Sublethal Cartap treatment induced an initial hypertrophy of the neurosecretory cells of NPO and NLT followed by loss of staining affinity as well as varying degrees of cytoplasmic vacuolization and necrosis. Herring bodies (HB) were also encountered in the neurohypophysis of the treated fishes.

  3. Toxicity and sublethal effects of six insecticides to last instar larvae and adults of the biocontrol agents Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) and Adalia bipunctata (L.) (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Garzón, A; Medina, P; Amor, F; Viñuela, E; Budia, F

    2015-08-01

    To further develop Integrated Pest Management (IPM) strategies against crop pests, it is important to evaluate the effects of insecticides on biological control agents. Therefore, we tested the toxicity and sublethal effects (fecundity and fertility) of flonicamid, flubendiamide, metaflumizone, spirotetramat, sulfoxaflor and deltamethrin on the natural enemies Chrysoperla carnea and Adalia bipunctata. The side effects of the active ingredients of the insecticides were evaluated with residual contact tests for the larvae and adults of these predators in the laboratory. Flonicamid, flubendiamide, metaflumizone and spirotetramat were innocuous to last instar larvae and adults of C. carnea and A. bipunctata. Sulfoxaflor was slightly toxic to adults of C. carnea and was highly toxic to the L4 larvae of A. bipunctata. For A. bipunctata, sulfoxaflor and deltamethrin were the most damaging compounds with a cumulative larval mortality of 100%. Deltamethrin was also the most toxic compound to larvae and adults of C. carnea. In accordance with the results obtained, the compounds flonicamid, flubendiamide, metaflumizone and spirotetramat might be incorporated into IPM programs in combination with these natural enemies for the control of particular greenhouse pests. Nevertheless, the use of sulfoxaflor and deltamethrin in IPM strategies should be taken into consideration when releasing either of these biological control agents, due to the toxic behavior observed under laboratory conditions. The need for developing sustainable approaches to combine the use of these insecticides and natural enemies within an IPM framework is discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Effects of sublethal concentrations of bifenthrin and deltamethrin on fecundity, growth, and development of the honeybee Apis mellifera ligustica.

    Science.gov (United States)

    Dai, Ping-Li; Wang, Qiang; Sun, Ji-Hu; Liu, Feng; Wang, Xing; Wu, Yan-Yan; Zhou, Ting

    2010-03-01

    Bifenthrin and deltamethrin have been widely used as pesticides in agriculture and forestry and are becoming an increasing risk to honeybees. The honeybee, Apis mellifera ligustica, is widely recognized as a beneficial insect of agronomic, ecological, and scientific importance. It is important to understand what effects these chemicals have on bees. Effects of two pesticides at sublethal concentrations on fecundity, growth, and development of honeybees were examined with the feeding method for a three-year period (2006-2008). It was shown that both bifenthrin and deltamethrin significantly reduced bee fecundity, decreased the rate at which bees develop to adulthood, and increased their immature periods. The toxicity of bifenthrin and deltamethrin on workers of Apis mellifera ligustica was also assessed, and the results from the present study showed that the median lethal effects of bifenthrin and deltamethrin were 16.7 and 62.8 mg/L, respectively.

  5. Effects of acute sublethal gamma radiation exposure on aggressive behavior in male mice: A dose-response study

    International Nuclear Information System (INIS)

    Maier, D.M.; Landauer, M.R.

    1989-01-01

    The resident-intruder paradigm was used to assess the effects of gamma radiation (0, 3, 5, 7 Gray [Gy] cobalt-60) on aggressive offensive behavior in resident male mice over a 3-month period. The defensive behavior of nonirradiated intruder mice was also monitored. A dose of 3 Gy had no effect on either the residents' offensive behavior or the defensive behavior of the intruders paired with them. Doses of 5 and 7 Gy produced decreases in offensive behavior of irradiated residents during the second week postirradiation. The nonirradiated intruders paired with these animals displayed decreases in defensive behavior during this time period, indicating a sensitivity to changes in the residents' behavior. After the third week postirradiation, offensive and defensive behavior did not differ significantly between irradiated mice and sham-irradiated controls. This study suggests that sublethal doses of radiation can temporarily suppress aggressive behavior but have no apparent permanent effect on that behavior

  6. Effect of sublethal doses of radiation and cystamine on the dynamics of Rana temporaria L. larvae development

    International Nuclear Information System (INIS)

    Popov, D.V.

    1979-01-01

    The longevity of Rana temporaria L. larvae in the 45th stage of development is studied after irradiation in sublethal doses (10.000-20.000 R) and irradiation with preliminary cystamine protection. It has been shown that the protective effect of cystamine is revealed in partial normalization of the larvae development rate but does not eliminate the typical anomalies of extremity development and does not prolong the time of animal survival. It has been found that LD 50/30 dose for R. temporaria tadpoles in the 45th stage of development is slightly higher than 10.000 R. The selective effect of X-radiation on the formative bonds at cornea induction in Anura larvae is concluded

  7. The sublethal effects of endosulfan on the circadian rhythms and locomotor activity of two sympatric parasitoid species.

    Science.gov (United States)

    Delpuech, Jean-Marie; Bussod, Sophie; Amar, Aurelien

    2015-08-01

    The organochlorine insecticide endosulfan is dispersed worldwide and significantly contributes to environmental pollution. It is an antagonist of the neurotransmitter gamma-aminobutyric acid (GABA), which is also indirectly involved in photoperiodic time measurement. In this study, we show that endosulfan at a dose as low as LC 0.1 modified the rhythm of locomotor activity of two sympatric parasitoid species, Leptopilina boulardi and Leptopilina heterotoma. The insecticide strongly increased the nocturnal activity of both species and synchronized their diurnal activity; these activities were not synchronized under control conditions. Parasitoids are important species in ecosystems because they control the populations of other insects. In this paper, we discuss the possible consequences of these sublethal effects and highlight the importance of such effects in evaluating the consequences of environmental pollution due to insecticides. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Sublethal effects of fenpyroximate and pyridaben on two predatory mite species, Neoseiulus womersleyi and Phytoseiulus persimilis (Acari, Phytoseiidae).

    Science.gov (United States)

    Park, Jung-Joon; Kim, Minsik; Lee, Joon-Ho; Shin, Key-Il; Lee, Sung Eun; Kim, Jeong-Gyu; Cho, Kijong

    2011-07-01

    Laboratory bioassays were conducted to evaluate the sublethal effects of fenpyroximate and pyridaben on life-table parameters of two predatory mites species, Neoseiulus (= Amblyseius) womersleyi and Phytoseiulus persimilis. In these assays, young adult females were treated with three sublethal concentrations of each acaricide. The life-table parameters were calculated at each acaricide concentration, and compared using bootstrap procedures. For each acaricide, the LC(50) estimates for both species were similar, yet the two species exhibited completely different susceptibility when the population growth rate was used as the endpoint. Exposure to both acaricides reduced the net reproduction rate (R (o)) in a concentration-dependent manner and their EC(50)s were equivalent to less than LC(7). Two different scales of population-level endpoints were estimated to compare the total effect between the species and treatments: the first endpoint values were based on the net reproductive rate (fecundity λ) and the second endpoint values incorporated the mean egg hatchability into the net reproductive rate (vitality λ). The fecundity λ decreased in a concentration-dependent manner for both acaricide treatments, but the vitality λ decreased abruptly after treatment of N. womersleyi with pyridaben. The change in the patterns of λ revealed that the acaricide effects at the population level strongly depended on the life-history characteristics of the predatory mite species and the chemical mode of action. When the total effects of the two acaricides on N. womersleyi and P. persimilis were considered, fenpyroximate was found to be the most compatible acaricide for the augmentative release of N. womersleyi after treatment.

  9. Sub-lethal effects of pesticide residues in brood comb on worker honey bee (Apis mellifera development and longevity.

    Directory of Open Access Journals (Sweden)

    Judy Y Wu

    Full Text Available BACKGROUND: Numerous surveys reveal high levels of pesticide residue contamination in honey bee comb. We conducted studies to examine possible direct and indirect effects of pesticide exposure from contaminated brood comb on developing worker bees and adult worker lifespan. METHODOLOGY/PRINCIPAL FINDINGS: Worker bees were reared in brood comb containing high levels of known pesticide residues (treatment or in relatively uncontaminated brood comb (control. Delayed development was observed in bees reared in treatment combs containing high levels of pesticides particularly in the early stages (day 4 and 8 of worker bee development. Adult longevity was reduced by 4 days in bees exposed to pesticide residues in contaminated brood comb during development. Pesticide residue migration from comb containing high pesticide residues caused contamination of control comb after multiple brood cycles and provided insight on how quickly residues move through wax. Higher brood mortality and delayed adult emergence occurred after multiple brood cycles in contaminated control combs. In contrast, survivability increased in bees reared in treatment comb after multiple brood cycles when pesticide residues had been reduced in treatment combs due to residue migration into uncontaminated control combs, supporting comb replacement efforts. Chemical analysis after the experiment confirmed the migration of pesticide residues from treatment combs into previously uncontaminated control comb. CONCLUSIONS/SIGNIFICANCE: This study is the first to demonstrate sub-lethal effects on worker honey bees from pesticide residue exposure from contaminated brood comb. Sub-lethal effects, including delayed larval development and adult emergence or shortened adult longevity, can have indirect effects on the colony such as premature shifts in hive roles and foraging activity. In addition, longer development time for bees may provide a reproductive advantage for parasitic Varroa destructor

  10. Effects of sub-lethal dose of γ-irradiation on lysosomal enzymes in tissue of pigeon

    International Nuclear Information System (INIS)

    Shah, V.C.; Gadhia, P.K.

    1979-01-01

    Effects of total body γ-irradiation with sub-lethal dose (300 rad) on three lysosomal enzymes namely acid phosphatase, ribonuclease-II and deoxyribonuclease-II have been studied in pigeons. Liver, kidney and spleen were the tissues studied at different intervals like 1-h, 24-h, 48-h, and 72-h of irradiation. The specific activities ('crude' fraction) of acid phosphatase and ribonuclease-II increased significantly in spleen and liver at 48-h of irradiation. The activity of deoxyribonuclease-II in liver and spleen was increased only at 72-h post-irradiation. On the other hand, the total activities of three lysosomal enzymes did not show remarkable change throughout 72-h of irradiation. (author)

  11. Assessment of acute sublethal effects of clothianidin on motor function of honeybee workers using video-tracking analysis.

    Science.gov (United States)

    Alkassab, Abdulrahim T; Kirchner, Wolfgang H

    2018-01-01

    Sublethal impacts of pesticides on the locomotor activity might occur to different degrees and could escape visual observation. Therefore, our objective is the utilization of video-tracking to quantify how the acute oral exposure to different doses (0.1-2ng/bee) of the neonicotinoid "clothianidin" influences the locomotor activity of honeybees in a time course experiment. The total distance moved, resting time as well as the duration and frequency of bouts of laying upside down are measured. Our results show that bees exposed to acute sublethal doses of clothianidin exhibit a significant increase in the total distance moved after 30 and 60min of the treatment at the highest dose (2ng/bee). Nevertheless, a reduction of the total distance is observed at this dose 90min post-treatment compared to the distance of the same group after 30min, where the treated bees show an arched abdomen and start to lose their postural control. The treated bees with 1ng clothianidin show a significant increase in total distance moved over the experimental period. Moreover, a reduction in the resting time and increase of the duration and frequency of bouts of laying upside down at these doses are found. Furthermore, significant effects on the tested parameters are observed at the dose (0.5ng/bee) first at 60min post-treatment compared to untreated bees. The lowest dose (0.1ng/bee) has non-significant effects on the motor activity of honeybees compared to untreated bees over the experimental period. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Effects of Sublethal Fungicides on Mutation Rates and Genomic Variation in Fungal Plant Pathogen, Sclerotinia sclerotiorum.

    Science.gov (United States)

    Amaradasa, B Sajeewa; Everhart, Sydney E

    2016-01-01

    Pathogen exposure to sublethal doses of fungicides may result in mutations that may represent an important and largely overlooked mechanism of introducing new genetic variation into strictly clonal populations, including acquisition of fungicide resistance. We tested this hypothesis using the clonal plant pathogen, Sclerotinia sclerotiorum. Nine susceptible isolates were exposed independently to five commercial fungicides with different modes of action: boscalid (respiration inhibitor), iprodione (unclear mode of action), thiophanate methyl (inhibition of microtubulin synthesis) and azoxystrobin and pyraclostrobin (quinone outside inhibitors). Mycelium of each isolate was inoculated onto a fungicide gradient and sub-cultured from the 50-100% inhibition zone for 12 generations and experiment repeated. Mutational changes were assessed for all isolates at six neutral microsatellite (SSR) loci and for a subset of isolates using amplified fragment length polymorphisms (AFLPs). SSR analysis showed 12 of 85 fungicide-exposed isolates had a total of 127 stepwise mutations with 42 insertions and 85 deletions. Most stepwise deletions were in iprodione- and azoxystrobin-exposed isolates (n = 40/85 each). Estimated mutation rates were 1.7 to 60-fold higher for mutated loci compared to that expected under neutral conditions. AFLP genotyping of 33 isolates (16 non-exposed control and 17 fungicide exposed) generated 602 polymorphic alleles. Cluster analysis with principal coordinate analysis (PCoA) and discriminant analysis of principal components (DAPC) identified fungicide-exposed isolates as a distinct group from non-exposed control isolates (PhiPT = 0.15, P = 0.001). Dendrograms based on neighbor-joining also supported allelic variation associated with fungicide-exposure. Fungicide sensitivity of isolates measured throughout both experiments did not show consistent trends. For example, eight isolates exposed to boscalid had higher EC50 values at the end of the experiment, and

  13. Effects of Sublethal Fungicides on Mutation Rates and Genomic Variation in Fungal Plant Pathogen, Sclerotinia sclerotiorum.

    Directory of Open Access Journals (Sweden)

    B Sajeewa Amaradasa

    Full Text Available Pathogen exposure to sublethal doses of fungicides may result in mutations that may represent an important and largely overlooked mechanism of introducing new genetic variation into strictly clonal populations, including acquisition of fungicide resistance. We tested this hypothesis using the clonal plant pathogen, Sclerotinia sclerotiorum. Nine susceptible isolates were exposed independently to five commercial fungicides with different modes of action: boscalid (respiration inhibitor, iprodione (unclear mode of action, thiophanate methyl (inhibition of microtubulin synthesis and azoxystrobin and pyraclostrobin (quinone outside inhibitors. Mycelium of each isolate was inoculated onto a fungicide gradient and sub-cultured from the 50-100% inhibition zone for 12 generations and experiment repeated. Mutational changes were assessed for all isolates at six neutral microsatellite (SSR loci and for a subset of isolates using amplified fragment length polymorphisms (AFLPs. SSR analysis showed 12 of 85 fungicide-exposed isolates had a total of 127 stepwise mutations with 42 insertions and 85 deletions. Most stepwise deletions were in iprodione- and azoxystrobin-exposed isolates (n = 40/85 each. Estimated mutation rates were 1.7 to 60-fold higher for mutated loci compared to that expected under neutral conditions. AFLP genotyping of 33 isolates (16 non-exposed control and 17 fungicide exposed generated 602 polymorphic alleles. Cluster analysis with principal coordinate analysis (PCoA and discriminant analysis of principal components (DAPC identified fungicide-exposed isolates as a distinct group from non-exposed control isolates (PhiPT = 0.15, P = 0.001. Dendrograms based on neighbor-joining also supported allelic variation associated with fungicide-exposure. Fungicide sensitivity of isolates measured throughout both experiments did not show consistent trends. For example, eight isolates exposed to boscalid had higher EC50 values at the end of the

  14. Effects of Sublethal Fungicides on Mutation Rates and Genomic Variation in Fungal Plant Pathogen, Sclerotinia sclerotiorum

    Science.gov (United States)

    Amaradasa, B. Sajeewa

    2016-01-01

    Pathogen exposure to sublethal doses of fungicides may result in mutations that may represent an important and largely overlooked mechanism of introducing new genetic variation into strictly clonal populations, including acquisition of fungicide resistance. We tested this hypothesis using the clonal plant pathogen, Sclerotinia sclerotiorum. Nine susceptible isolates were exposed independently to five commercial fungicides with different modes of action: boscalid (respiration inhibitor), iprodione (unclear mode of action), thiophanate methyl (inhibition of microtubulin synthesis) and azoxystrobin and pyraclostrobin (quinone outside inhibitors). Mycelium of each isolate was inoculated onto a fungicide gradient and sub-cultured from the 50–100% inhibition zone for 12 generations and experiment repeated. Mutational changes were assessed for all isolates at six neutral microsatellite (SSR) loci and for a subset of isolates using amplified fragment length polymorphisms (AFLPs). SSR analysis showed 12 of 85 fungicide-exposed isolates had a total of 127 stepwise mutations with 42 insertions and 85 deletions. Most stepwise deletions were in iprodione- and azoxystrobin-exposed isolates (n = 40/85 each). Estimated mutation rates were 1.7 to 60-fold higher for mutated loci compared to that expected under neutral conditions. AFLP genotyping of 33 isolates (16 non-exposed control and 17 fungicide exposed) generated 602 polymorphic alleles. Cluster analysis with principal coordinate analysis (PCoA) and discriminant analysis of principal components (DAPC) identified fungicide-exposed isolates as a distinct group from non-exposed control isolates (PhiPT = 0.15, P = 0.001). Dendrograms based on neighbor-joining also supported allelic variation associated with fungicide-exposure. Fungicide sensitivity of isolates measured throughout both experiments did not show consistent trends. For example, eight isolates exposed to boscalid had higher EC50 values at the end of the experiment

  15. Effects of Sublethal Concentrations of Cyantraniliprole on the Development, Fecundity and Nutritional Physiology of the Black Cutworm Agrotis ipsilon (Lepidoptera: Noctuidae.

    Directory of Open Access Journals (Sweden)

    Chunmei Xu

    Full Text Available To better understand the sublethal effects of cyantraniliprole on the black cutworm Agrotis ipsilon (Lepidoptera: Noctuidae, several studies were carried out to investigate sublethal effects on development stages, population parameters, feeding indices and nutrient content of A. ipsilon. The result of a bioassay showed that cyantraniliprole had high toxicity against A. ipsilon fourth-instar larvae with an LC50 of 0.354 μg.g-1 using an artificial diet. Compared with controls, sublethal doses of cyantraniliprole at LC5, LC20 and LC40 levels prolonged larval and pupal duration and extended mean generation time and total preovipositional period. In addition, survival rate, reproductive value, intrinsic and finite rates of increase and net reproduction rate declined significantly. Meanwhile, cyantraniliprole had markedly antifeedant effects; decreased the relative growth rate (RGR, the relative consumption rate (RCR, the efficiency of conversion of ingested food (ECI, the efficiency of conversion of digested food (ECD; and increased the approximate digestibility (AD significantly. This phenomenon contributed to the decrease of nutrient contents, including lipids, protein and carbohydrates, to the point that insufficient energy was available for normal growth. Therefore, sublethal concentrations of cyantraniliprole decreased growth speed and reduced population reproduction of A. ipsilon. This result provides information useful in integrated pest management (IPM programs for A. ipsilon.

  16. Sublethal effects of diazinon, fenitrothion and chlorpyrifos on the functional response of predatory bug, Andrallus spinidens Fabricius (Hem.: Pentatomidae in the laboratory conditions

    Directory of Open Access Journals (Sweden)

    Moloud GholamzadehChitgar

    2014-04-01

    Full Text Available The sublethal effects of diazinon, fenitrothion and chlorpyrifos on the functional response of predatory bug, Andrallus spinidens Fabricius (Hem.: Pentatomidae, a potential biological control agent, were studied on 5th-instar nymphs. The experiment was conducted in varying densities (2, 4, 8, 16, 32 and 64 of last instars larvae of Chilo suppressalis Walker (Lepidoptera: Pyralidae as prey at 25 ± 2 °C, 60% ± 10% relative humidity (RH and a photoperiod of 16:8 h (L: D. The results of logistic regressions revealed a type II functional response in the control and all insecticide treatments. Comparison of functional response curves revealed that tested insecticides markedly decreased the mean of preys consumed by A. spinidens. Among them, functional response curve of A. spinidens in chlorpyrifos treatment was significantly lower than the other treatments. In this study, application of insecticides caused a decrease in the attack rate and an increase in the handling time of exposed bugs compared with the control. The longest handling time (3.97 ± 0.62 and the lowest attack rate (0.023 ± 0.007 were observed in chlorpyrifos and fenitrothion treatments, respectively. The results suggested that the adverse effect of these insecticides on A. spinidens should be considered in integrated pest management programs (IPM.

  17. Low-salinity stress in the American lobster, Homarus americanus, after chronic sublethal exposure to cadmium: Biochemical effects

    Energy Technology Data Exchange (ETDEWEB)

    Gould, E

    1980-01-01

    Lobsters (Homarus americanus) were exposed to cadmium (6 ..mu..g 1sup(-1), 30 days) in flowing seawater, then held for 7 days in aerated 'clean' seawater at either ambient (27 per mill) or low (17 per mill) salinity. Cadmium exposure alone (ambient salinity) induced a general elevation of enzyme activity (heart, antennal gland, and muscle MDH; heart LDH and GPI), despite the probability of some clearance of cadmium from body tissues during the 'clean' seawater holding period. Low-salinity alone (non-exposed lobsters) caused a decrease of enzyme activity (AAT, LDH, GPI, PK) in most tissues examined, except for tail muscle IDH, the activity of which was increased, and MDH, which was significantly elevated above ambient controls in all tissues except heart. Most low-salinity effects were observed in tail muscle, and most cadmium effects, in heart; low-salinity effects outnumbered cadmium stress by nine to four. In heart and tail muscle of cadmium-exposed lobsters held at low salinity, each of the two stresses apparently operated to nullify the other's effects. The most prominent single biochemical response to these sublethal stresses was the elevation of MDH activity. The ratio MDH:LDH gave the clearest indication of overall relative stress.

  18. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

    Energy Technology Data Exchange (ETDEWEB)

    Pavlikova, Nela, E-mail: nela.pavlikova@lf3.cuni.cz [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic); Smetana, Pavel [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic); Halada, Petr [Laboratory of Molecular Structure Characterization, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague (Czech Republic); Kovar, Jan [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic)

    2015-10-15

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. - Highlights: • Epidemiologic studies connect pollution with incidence of diabetes mellitus. • We explored the effect of DDT and DDE on protein expression in the NES2Y pancreatic beta cell line. • One month exposure to three sublethal concentrations of DDT and DDE was employed. • Expression of alpha-enolase, actin

  19. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

    International Nuclear Information System (INIS)

    Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

    2015-01-01

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. - Highlights: • Epidemiologic studies connect pollution with incidence of diabetes mellitus. • We explored the effect of DDT and DDE on protein expression in the NES2Y pancreatic beta cell line. • One month exposure to three sublethal concentrations of DDT and DDE was employed. • Expression of alpha-enolase, actin

  20. Sublethal effects of tritium on aquatic systems. Ecological effects of lithium and beryllium on aquatic communities. Teratological effects of low-level magnetic fields

    International Nuclear Information System (INIS)

    Strand, J.A.; Poston, T.M.; Skalaski, J.R.; Emery, R.M.; Klopfer, D.C.; Abernethy, C.S.

    1981-01-01

    Studies of the sublethal effects of tritium on the relatively radiosensitive immune process of the rainbow trout suggest that a higher RBE value than is now recognized by the International Commission on Radiological Protection (ICRP) may be required. Studies included an evaluation of potential toxicity of lithium on embryological life of rainbow trout and an assessment of fate and effects of lithium in artificial stream habitats. Levels of lithium necessary to cause an observed effect would have to be at least three orders of magnitude above observed background. Studies on teratogenic effects of low-level magnetic fields address the need to assess the potential harmful effects of magnetic fields on attendant personnel working in the transport and hot cell areas of fusion reactors

  1. Multibiomarker assessment of cerium dioxide nanoparticle (nCeO{sub 2}) sublethal effects on two freshwater invertebrates, Dreissena polymorpha and Gammarus roeseli

    Energy Technology Data Exchange (ETDEWEB)

    Garaud, M. [Université de Lorraine, CNRS UMR 7360, Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Campus Bridoux, Rue du Général Delestraint, 57070 Metz (France); International Consortium for the Environmental Implications of Nanotechnology (iCEINT), Aix en Provence (France); Trapp, J.; Devin, S.; Cossu-Leguille, C.; Pain-Devin, S.; Felten, V. [Université de Lorraine, CNRS UMR 7360, Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Campus Bridoux, Rue du Général Delestraint, 57070 Metz (France); Giamberini, L., E-mail: laure.giamberini@univ-lorraine.fr [Université de Lorraine, CNRS UMR 7360, Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Campus Bridoux, Rue du Général Delestraint, 57070 Metz (France); International Consortium for the Environmental Implications of Nanotechnology (iCEINT), Aix en Provence (France)

    2015-01-15

    Highlights: • Gammarids and mussels both accumulated significant amount of waterborne nCeO{sub 2}. • nCeO{sub 2} decreased catalase, lysosomal system size and lipoperoxidation in mussels. • nCeO{sub 2} could exert antioxidant protecting activity in mussels. • In contrast with mussels, no effects of nCeO{sub 2} were observed on Gammarids. - Abstract: Cerium nanoparticles (nCeO{sub 2}) are widely used in everyday products, as fuel and paint additives. Meanwhile, very few studies on nCeO{sub 2} sublethal effects on aquatic organisms are available. We tried to fill this knowledge gap by investigating short-term effects of nCeO{sub 2} at environmentally realistic concentrations on two freshwater invertebrates; the amphipod Gammarus roeseli and the bivalve Dreissena polymorpha, using an integrated multibiomarker approach to detect early adverse effects of nCeO{sub 2} on organism biology. Differences in the behaviour of the organisms and of nanoparticles in the water column led to differential nCeO{sub 2} bioaccumulations, G. roeseli accumulating more cerium than D. polymorpha. Exposure to nCeO{sub 2} led to decreases in the size of the lysosomal system, catalase activity and lipoperoxidation in mussel digestive glands that could result from nCeO{sub 2} antioxidant properties, but also negatively impacted haemolymph ion concentrations. At the same time, no strong adverse effects of nCeO{sub 2} could be observed on G. roeseli. Further experiments will be necessary to confirm the absence of severe nCeO{sub 2} adverse effects in long-term environmentally realistic conditions.

  2. Predicting sublethal effects of herbicides on terrestrial non-crop plant species in the field from greenhouse data

    International Nuclear Information System (INIS)

    Riemens, Marleen M.; Dueck, Thom; Kempenaar, Corne

    2008-01-01

    Guidelines provided by OECD and EPPO allow the use of data obtained in greenhouse experiments in the risk assessment for pesticides to non-target terrestrial plants in the field. The present study was undertaken to investigate the predictability of effects on field-grown plants using greenhouse data. In addition, the influence of plant development stage on plant sensitivity and herbicide efficacy, the influence of the surrounding vegetation on individual plant sensitivity and of sublethal herbicide doses on the biomass, recovery and reproduction of non-crop plants was studied. Results show that in the future, it might well be possible to translate results from greenhouse experiments to field situations, given sufficient experimental data. The results also suggest consequences at the population level. Even when only marginal effects on the biomass of non-target plants are expected, their seed production and thereby survival at the population level may be negatively affected. - The response of greenhouse-grown wild plant species to herbicide exposure could be related to the response of the same species when grown in the field

  3. Sublethal effects of catch-and-release fishing: measuring capture stress, fish impairment, and predation risk using a condition index

    Science.gov (United States)

    Campbell, Matthew D.; Patino, Reynaldo; Tolan, J.M.; Strauss, R.E.; Diamond, S.

    2009-01-01

    The sublethal effects of simulated capture of red snapper (Lutjanus campechanus) were analysed using physiological responses, condition indexing, and performance variables. Simulated catch-and-release fishing included combinations of depth of capture and thermocline exposure reflective of environmental conditions experienced in the Gulf of Mexico. Frequency of occurrence of barotrauma and lack of reflex response exhibited considerable individual variation. When combined into a single condition or impairment index, individual variation was reduced, and impairment showed significant increases as depth increased and with the addition of thermocline exposure. Performance variables, such as burst swimming speed (BSS) and simulated predator approach distance (AD), were also significantly different by depth. BSSs and predator ADs decreased with increasing depth, were lowest immediately after release, and were affected for up to 15 min, with longer recovery times required as depth increased. The impairment score developed was positively correlated with cortisol concentration and negatively correlated with both BSS and simulated predator AD. The impairment index proved to be an efficient method to estimate the overall impairment of red snapper in the laboratory simulations of capture and shows promise for use in field conditions, to estimate release mortality and vulnerability to predation.

  4. Radio-induced neuropathology: from early effects to late sequelae. Rat behavioural and metabolic studies after sublethal total body irradiation

    International Nuclear Information System (INIS)

    Martigne, A.P.

    2010-05-01

    The radioresistance dogma of Central Nervous System (CNS) is now obsolete. Recent progress in neuroscience allow us to reconsider the radiation-induced cognitive dysfunctions observed after radiation therapy or after a nuclear accident, and to devise appropriate diagnostic and therapeutic means. We have developed a Rat model to study the effects of total body irradiation at a sublethal dose (4.5 Gy). This leads to impaired learning and memory of a task being acquired during the first month - which is prevented by administration of a radioprotector (amifostine) - while it does not appear to affect retrograde memory. Early, an apoptotic wave occurs in the sub-ventricular zone, 5 to 9 hours after exposure, while neuro-genesis is suppressed. Two days after irradiation, the metabolic study conducted by NMR HRMAS (High Resolution Magic Angle Spinning) suggests the presence of cerebral oedema and the study of brain lipids in liquid NMR confirms the membrane damages (elevated cholesterol and phospholipids). The lipid profile is then normalized while a gliosis appears. Finally, 1 month post-irradiation, the elevation of GABA, an inhibitory neurotransmitter, in 2 separate brain structures, occurs simultaneously with a taurine decrease in the hippocampus that lasts 6 months. Our integrated model allows validating bio-markers measurable in vivo NMR spectroscopy - the next experimental stage - and testing new radiation-protective agents. (author)

  5. Quantifying sublethal effects of glyphosate and Roundup® to Daphnia magna using a fluorescence based enzyme activity assay and video tracking

    DEFF Research Database (Denmark)

    Roslev, Peter; R. Hansen, Lone; Ørsted, Michael

    Glyphosate (N-(phosphonomethyl)glycine) is the active ingredient in a range of popular broad-spectrum, non-selective herbicide formulations. The toxicity of this herbicide to non-target aquatic organisms such as Daphnia magna is often evaluated using conventional toxicity assays that focus...... on endpoints such as immobility and mortality. In this study, we investigated sublethal effects of glyphosate and Roundup® to D. magna using video tracking for quantifying behavioral changes, and a novel fluorescence based assay for measuring in vivo hydrolytic enzyme activity (FLEA assay). Roundup® exposure...... resulted in concentration-dependent inhibition of alkaline phosphatase activity in D. magna. The inhibition of alkaline phosphatase by Roundup® was temperature-dependent with lowest inhibition at 14 °C and greater inhibition at 20 and 26 °C. Exposure of D. magna to sublethal concentrations of glyphosate...

  6. Effects of sublethal exposure to boric acid sugar bait on adult survival, host-seeking, bloodfeeding behavior, and reproduction of Stegomyia albopicta.

    Science.gov (United States)

    Ali, Arshad; Xue, Rui-De; Barnard, Donald R

    2006-09-01

    Effects of sublethal exposure to 0.1% boric acid sugar bait on adult survival, host-seeking, bloodfeeding behavior, and reproduction of Stegomyia albopicta were studied in the laboratory. Survival of males as well as females was significantly reduced when exposed to the bait, compared to control adults. The host-seeking and bloodfeeding activities in the baited females decreased, but the mean duration of blood engorgement (probing to voluntary withdrawal of proboscis) was not significantly different between the baited and control females. The landing and biting rates (human forearm) were significantly reduced in the baited females compared to nonbaited controls. Fecundity and fertility (based on number of laid eggs per female and percentage egg hatch, respectively) in the baited females were significantly reduced, and ovarian development was retarded. Sublethal exposure to sugar-based boric acid bait has the potential to reduce adult populations of St. albopicta.

  7. Detailed monitoring of a small but recovering population reveals sublethal effects of disease and unexpected interactions with supplemental feeding.

    Science.gov (United States)

    Tollington, Simon; Greenwood, Andrew; Jones, Carl G; Hoeck, Paquita; Chowrimootoo, Aurélie; Smith, Donal; Richards, Heather; Tatayah, Vikash; Groombridge, Jim J

    2015-07-01

    Infectious diseases are widely recognized to have substantial impact on wildlife populations. These impacts are sometimes exacerbated in small endangered populations, and therefore, the success of conservation reintroductions to aid the recovery of such species can be seriously threatened by outbreaks of infectious disease. Intensive management strategies associated with conservation reintroductions can further compound these negative effects in such populations. Exploring the sublethal effects of disease outbreaks among natural populations is challenging and requires longitudinal, individual life-history data on patterns of reproductive success and other indicators of individual fitness. Long-term monitoring data concerning detailed reproductive information of the reintroduced Mauritius parakeet (Psittacula echo) population collected before, during and after a disease outbreak was investigated. Deleterious effects of an outbreak of beak and feather disease virus (BFDV) were revealed on hatch success, but these effects were remarkably short-lived and disproportionately associated with breeding pairs which took supplemental food. Individual BFDV infection status was not predicted by any genetic, environmental or conservation management factors and was not associated with any of our measures of immune function, perhaps suggesting immunological impairment. Experimental immunostimulation using the PHA (phytohaemagglutinin assay) challenge technique did, however, provoke a significant cellular immune response. We illustrate the resilience of this bottlenecked and once critically endangered, island-endemic species to an epidemic outbreak of BFDV and highlight the value of systematic monitoring in revealing inconspicuous but nonetheless substantial ecological interactions. Our study demonstrates that the emergence of such an infectious disease in a population ordinarily associated with increased susceptibility does not necessarily lead to deleterious impacts on population

  8. Effects of Sub-lethal Concentrations of Silver Nanoparticles on a Simulated Intestinal Prokaryotic–Eukaryotic Interface

    Directory of Open Access Journals (Sweden)

    Elisa Garuglieri

    2018-01-01

    Full Text Available Nanotechnology applications are expected to bring a range of benefits to the food sector, aiming to provide better quality and conservation. In this research, the physiological response of both an Escherichia coli mono-species biofilm and Caco-2 intestinal cells to sub-lethal concentrations of silver nanoparticles (AgNPs has been investigated. In order to simulate the anaerobic and aerobic compartments required for bacteria and intestinal cells growth, a simplified semi-batch model based on a transwell permeable support was developed. Interaction between the two compartments was obtained by exposing Caco-2 intestinal cells to the metabolites secreted by E. coli biofilm after its exposure to AgNPs. To the best of the authors’ knowledge, this study is the first to investigate the effect of AgNPs on Caco-2 cells that takes into consideration previous AgNP-intestinal biofilm interactions, and at concentrations mimicking real human exposure. Our data show that 1 μg/mL AgNPs in anaerobic conditions (i promote biofilm formation up to 2.3 ± 0.3 fold in the first 72 h of treatment; (ii increase reactive oxygen species (ROS production to 84 ± 21% and change the physiological status of microbial cells after 96 h of treatment; (iii seriously affect a 72-h old established biofilm, increasing the level of oxidative stress to 86 ± 21%. Moreover, the results indicate that oxygen renders the biofilm more adequate to counteract AgNP effects. Comet assays on Caco-2 cells demonstrated a protective role of biofilm against the genotoxic effect of 1 μg/mL AgNPs on intestinal epithelial cells.

  9. Biological effects data: Fluoride and sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    McMechan, K.J. (ed.); Holton, R.L.; Ulbricht, R.J.; Morgan , J.B.

    1975-04-01

    The Alumax Pacific Aluminum Corporation has proposed construction of an aluminum reduction facility near Youngs Bay at Warrenton, Oregon. This report comprises one part of the final report to Alumax on a research project entitled, Physical, Chemical and Biological Studies of Youngs Bay.'' It presents data pertaining to the potential biological effects of fluoride and sulfur dioxide, two potentially hazardous plant-stack emissions, on selected aquatic species of the area. Companion volumes provide a description of the physical characteristics the geochemistry, and the aquatic animals present in Youngs Bay and adjacent ecosystems. An introductory volume provides general information and maps of the area, and summarizes the conclusions of all four studies. The data from the two phases of the experimental program are included in this report: lethal studies on the effects of selected levels of fluoride and sulfur dioxide on the survival rate of eleven Youngs Bay faunal species from four phyla, and sublethal studies on the effects of fluoride and sulfur dioxide on the rate of primary production of phytoplankton. 44 refs., 18 figs., 38 tabs.

  10. Lethal and sub-lethal effects of five pesticides used in rice farming on the earthworm Eisenia fetida

    NARCIS (Netherlands)

    Rico, Andreu; Sabater, Consuelo; Castillo, María Ángeles

    2016-01-01

    The toxicity of five pesticides typically used in rice farming (trichlorfon, dimethoate, carbendazim, tebuconazole and prochloraz) was evaluated on different lethal and sub-lethal endpoints of the earthworm Eisenia fetida. The evaluated endpoints included: avoidance behaviour after an exposure

  11. Biological radiation effects

    International Nuclear Information System (INIS)

    Kiefer, J.

    1989-01-01

    The book covers all aspects of biological radiation effects. The physical basis is dealt with in some detail, and the effects at the subcellular and the cellular level are discussed, taking into account modern developments and techniques. The effects on the human organism are reviewed, both from the point of view of applications in medicine as well as with regard to radiation hazards (teratogenic, gonadal and carcinogenic effects)

  12. Biological Effects of Radiation

    International Nuclear Information System (INIS)

    Jatau, B.D.; Garba, N.N.; Yusuf, A.M.; Yamusa, Y. A.; Musa, Y.

    2013-01-01

    In earlier studies, researchers aimed a single particle at the nucleus of the cell where DNA is located. Eighty percent of the cells shot through the nucleus survived. This contradicts the belief that if radiation slams through the nucleus, the cell will die. But the bad news is that the surviving cells contained mutations. Cells have a great capacity to repair DNA, but they cannot do it perfectly. The damage left behind in these studies from a single particle of alpha radiation doubled the damage that is already there. This proved, beyond a shadow of doubt, those there biological effects occur as a result of exposure to radiation, Radiation is harmful to living tissue because of its ionizing power in matter. This ionization can damage living cells directly, by breaking the chemical bonds of important biological molecules (particularly DNA), or indirectly, by creating chemical radicals from water molecules in the cells, which can then attack the biological molecules chemically. At some extent these molecules are repaired by natural biological processes, however, the effectiveness of this repair depends on the extent of the damage. The interaction of ionizing with the human body, arising either from external sources outside the body or from internal contamination of the body by radioactive materials, leads to the biological effects which may later show up as a clinical symptoms. Basically, this formed the baseline of this research to serve as a yardstick for creating awareness about radiation and its resulting effects.

  13. The Effect of A Single Sub-Lethal Dose of Whole Body Irradiation on the Small Intestine of Rats

    International Nuclear Information System (INIS)

    Al-Ramli, M. A.; Kubba, M. A.; Al-Bassam, L. S.; Belhaj, K.; Al-shawish, N. M.

    2007-01-01

    The effect of whole body radiation with a single sub-lethal dose at 4 Gy on rat small intestine was studied histologically and quantitatively. Irradiated animals were euthanized at 24 hours, 3, 7, 14, 21 and 28 days post- irradiation. Crypts of Leiberkuhn and peyer's patches were especially targeted by irradiation. The crypts showed severe cellular fragmentation in the germinal cellular compartments twenty Four hours after irradiation resulting in partial denudation of villi especially at their Tips. At three days, these cells resumed their proliferative activity with the appearance of unusually large numbers of mitotic figures. Cellular regeneration in the crypts and on the villous surface showed improvement with advancing time till day 28 when the villi had complete epithelial covering and the proliferative activity of the germinal cryptic cells returned to normal. The quantitative study included the measurement of about fifty villi at each time after irradiation. A significant decrease in villous length was noticed at twenty four hours post-irradiation compared to the control values. The length of villi plateaued at about this level till day twenty one when it slightly increased to reach a sub normal mean length on day 28. We concluded that whole body irradiation with a single dose at 4 Gy was enough to induce cryptic cellular necrosis with sloughing of epithelial villous columnar covering. This cellular damage was, however, sub- total since quick regenerative cellular activity was noticed three days post-irradiation. The decrease in the villous length paralleled the cryptic cellular damage whereas full recovery was not achieved despite obvious cellular regeneration.

  14. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells.

    Science.gov (United States)

    Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

    2015-10-01

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Laboratory bioassays to estimate the lethal and sublethal effects of various insecticides and fungicides on Deraeocoris brevis (Hemiptera: Miridae).

    Science.gov (United States)

    Amarasekare, K G; Shearer, P W

    2013-04-01

    This laboratory bioassay focused on lethal and sublethal effects of five insecticides (chlorantraniliprole, cyantraniliprole, spinetoram, novaluron, and lambda-cyhalothrin) and two fungicide treatments (sulfur and a mixture of copper hydroxide and mancozeb) on the predatory mired bug, Deraeocoris brevis (Uhler) (Hemiptera: Miridae) using second instars and adult males and females. Formulated pesticides were tested using concentrations that were equivalent to the high label rate (1x) (high rate) and 1/10th of that amount (0.1x) (low rate) dissolved in 378.5 liters of water. Lambda-cyhalothrin was highly toxic to D. brevis nymphs and adults at both rates, whereas both rates of novaluron were highly toxic to nymphs. Cyantraniliprole, chlorantraniliprole, and novaluron were less toxic to adults, and chlorantraniliprole and spinetoram were less toxic to nymphs. Both rates of spinetoram caused significant mortality to adults. Fecundity of adult females was affected negatively by the high rates of either novaluron or spinetoram, whereas the fertility was affected only by the high rate of novaluron. The high rate of spinetoram reduced survival of nymphs. Adults treated with spinetoram had reduced longevity. Cyantraniliprole caused some mortality to nymphs and affected their survival. Both rates of sulfur were toxic to nymphs and affected emergence to adults. The mixture of copper hydroxide and mancozeb was less toxic to D. brevis. Neither adult longevity nor sex ratio was affected by the fungicides. The r values for D. brecis treated with lambda-cyhalothrin, novaluron, spinetoram, and sulfur were low, indicating that these products may have negative impact on population growth.

  16. Sublethal Effects of Imidacloprid on Honey Bee Colony Growth and Activity at Three Sites in the U.S.

    Science.gov (United States)

    Meikle, William G; Adamczyk, John J; Weiss, Milagra; Gregorc, Ales; Johnson, Don R; Stewart, Scott D; Zawislak, Jon; Carroll, Mark J; Lorenz, Gus M

    2016-01-01

    Imidacloprid is a neonicotinoid pesticide heavily used by the agricultural industry and shown to have negative impacts on honey bees above certain concentrations. We evaluated the effects of different imidacloprid concentrations in sugar syrup using cage and field studies, and across different environments. Honey bee colonies fed sublethal concentrations of imidicloprid (0, 5, 20 and 100 ppb) over 6 weeks in field trials at a desert site (Arizona), a site near intensive agriculture (Arkansas) and a site with little nearby agriculture but abundant natural forage (Mississippi) were monitored with respect to colony metrics, such as adult bee and brood population sizes, as well as pesticide residues. Hive weight and internal hive temperature were monitored continuously over two trials in Arizona. Colonies fed 100 ppb imidacloprid in Arizona had significantly lower adult bee populations, brood surface areas and average frame weights, and reduced temperature control, compared to colonies in one or more of the other treatment groups, and consumption rates of those colonies were lower compared to other colonies in Arizona and Arkansas, although no differences in capped brood or average frame weight were observed among treatments in Arkansas. At the Mississippi site, also rich in alternative forage, colonies fed 5 ppb imidacloprid had less capped brood than control colonies, but contamination of control colonies was detected. In contrast, significantly higher daily hive weight variability among colonies fed 5 ppb imidacloprid in Arizona suggested greater foraging activity during a nectar flow post treatment, than any other treatment group. Imidacloprid concentrations in stored honey corresponded well with the respective syrup concentrations fed to the colonies and remained stable within the hive for at least 7 months after the end of treatment.

  17. Effects of melatonin in rats in the initial third stage of pregnancy exposed to sub-lethal doses of herbicides.

    Science.gov (United States)

    Almeida, Lécio Leone de; Teixeira, Álvaro Aguiar Coelho; Soares, Anísio Francisco; Cunha, Franklin Magliano da; Silva, Valdemiro Amaro da; Vieira Filho, Leucio Duarte; Wanderley-Teixeira, Valéria

    2017-04-01

    Exposure to the herbicides Paraquat (PQ) and Roundup ® may cause cell lesions due to an increase in oxidative stress levels in different biological systems, even in the reproductive system. Evaluate the possible changes in reproductive parameters and hepatic, as well as its prevention by simultaneous application of melatonin. Thirty-five female rats at the age of 3 months were divided into seven groups: three groups exposed to sub-lethal doses of the herbicides PQ (50mg/kg) and Roundup ® (500mg/kg) (n=5, G2, G3 and G4); three groups exposed to herbicides and simultaneous treatment with 10mg/kg of Melatonin (n=5, G5, G6 and G7) and control group (n=5, G1) from the first to the seventh day of pregnancy. On the seventh day of pregnancy, the rats were anesthetized and euthanized, followed by laparotomy to remove their reproductive tissues and liver. Body and ovary weights were taken and the number of implantation sites, corpora lutea, preimplantation losses, implantation rates were counted and histopathology of the implantation sites, morphometry of the surface and glandular epithelia of endometrium and hepatic oxidative stress were undertaken. The present study shows the decrease in body and ovary weight, decrease in the number of implantation sites, implantation rate, in the total number of corpora lutea and increase of preimplantation percentages were observed when compared to the G1: Fig. 1 and Table 1, (p>0.001 ANOVA/Tukey). The histopathological analysis of the implantation sites showed a disorder of the cytotrophoblast and cell degeneration within the blastocyst cavity in Fig. 4. Morphometry revealed a reduction in surface and glandular epithelia and in the diameter of the endometrial glands (Table 2; p>0.05 ANOVA/Tukey), whereas in liver, serum levels of thiobarbituric acid reactive substances (TBARS) were found to be significantly elevated (Fig. 2; p>0.001; p>0.05 ANOVA/Tukey), and serum level of reduced glutathione (GSH) was significantly lower (Fig. 3; p>0

  18. Biological effects of hyperthermia

    International Nuclear Information System (INIS)

    Okumura, Hiroshi

    1980-01-01

    Biological effects of hyperthermia and application of hyperthermia to cancer therapy were outlined. As to independent effects of hyperthermia, heat sensitivity of cancer cells, targets of hyperthermia, thermal tolerance of cancer cells, effects of pH on hyperthermic cell survival, effects of hyperthermia on normal tissues, and possibility of clinical application of hyperthermia were described. Combined effect of hyperthermia and x-irradiation to enhance radiosensitivity of cancer cells, its mechanism, effects of oxygen on cancer cells treated with hyperthermia and irradiation, and therapeutic ratio of combined hyperthermia and irradiation were also described. Finally, sensitizers were mentioned. (Tsunoda, M.)

  19. Sublethal effects of cadmium, manganese, lead, zinc and iron on the ...

    African Journals Online (AJOL)

    caleb

    African Journal of Environmental Science and. Technology ... Studies on the effect of heavy metals on plasma electrolytes revealed that Pb caused elevated level of sodium .... relation to disease and drugs activity (Oyewole and. Malomo .... Further analysis was carried out only ..... cytoskeleton, membrane and DNA. Thus, an ...

  20. Sublethal effects of abamectin and fenpropathrin on the consumption of Tetranychus urticae eggs by Scolothrips longicornis

    DEFF Research Database (Denmark)

    Pakyari, Hajar; Enkegaard, Annie

    2015-01-01

    consumption rates of exposed females of Scolothrips longicornis Priesner and their offspring when fed on Tetranychus urticae Koch eggs. Prey consumption of female thrips was significantly affected by treatment with all concentrations of the two pesticides with the effect of fenpropathrin being more severe...

  1. Toxicity bioassay and effects of sub-lethal exposure of malathion on ...

    African Journals Online (AJOL)

    Ksu-network

    2012-04-26

    Apr 26, 2012 ... glutamate pyruvic transaminase. Non-target animals including fish are greatly affected by the indiscriminate use of these pesticides. Fish appear to posses the same biochemical pathways to deal with the toxic effects of endogenous and exogenous agents as mammalian species does (Lackner, 1998).

  2. Effects of clothianidin on aquatic communities: Evaluating the impacts of lethal and sublethal exposure to neonicotinoids

    OpenAIRE

    Miles, Jesse C.; Hua, Jessica; Sepulveda, Maria S.; Krupke, Christian H.; Hoverman, Jason T.

    2017-01-01

    The widespread usage of neonicotinoid insecticides has sparked concern over their effects on non-target organisms. While research has largely focused on terrestrial systems, the low soil binding and high water solubility of neonicotinoids, paired with their extensive use on the landscape, puts aquatic environments at high risk for contamination via runoff events. We assessed the potential threat of these compounds to wetland communities using a combination of field surveys and experimental ex...

  3. Effects of sublethal doses of gamma radiation on the developing rat brain

    International Nuclear Information System (INIS)

    Cerda, H.; Carlsson, J.; Larsson, B.; Saefwenberg, J.O.

    1975-01-01

    Newborn rats were irradiated with 60 Co gamma rays. Doses of 0, 80 or 160 rads were given to the whole body. The whole body and brain weights, DNA and RNA contents of the brain and 3 H-thymidine or 3 H-uridine incorporated by the brain were measured at 5, 10 or 15 days after birth. A dose of 160 rads produced clear alterations in the brain but no clear effects could be detected when 80 rads were given. (author)

  4. Effects of clothianidin on aquatic communities: Evaluating the impacts of lethal and sublethal exposure to neonicotinoids.

    Science.gov (United States)

    Miles, Jesse C; Hua, Jessica; Sepulveda, Maria S; Krupke, Christian H; Hoverman, Jason T

    2017-01-01

    The widespread usage of neonicotinoid insecticides has sparked concern over their effects on non-target organisms. While research has largely focused on terrestrial systems, the low soil binding and high water solubility of neonicotinoids, paired with their extensive use on the landscape, puts aquatic environments at high risk for contamination via runoff events. We assessed the potential threat of these compounds to wetland communities using a combination of field surveys and experimental exposures including concentrations that are representative of what invertebrates experience in the field. In laboratory toxicity experiments, LC50 values ranged from 0.002 ppm to 1.2 ppm for aquatic invertebrates exposed to clothianidin. However, freshwater snails and amphibian larvae showed high tolerance to the chemical with no mortality observed at the highest dissolvable concentration of the insecticide. We also observed behavioral effects of clothianidin. Water bugs, Belostoma flumineum, displayed a dose-dependent reduction in feeding rate following exposure to clothianidin. Similarly, crayfish, Orconectes propinquus, exhibited reduced responsiveness to stimulus with increasing clothianidin concentration. Using a semi-natural mesocosm experiment, we manipulated clothianidin concentration (0.6, 5, and 352 ppb) and the presence of predatory invertebrates to explore community-level effects. We observed high invertebrate predator mortality with increases in clothianidin concentration. With increased predator mortality, prey survival increased by 50% at the highest clothianidin concentration. Thus, clothianidin contamination can result in a top-down trophic cascade in a community dominated by invertebrate predators. In our Indiana field study, we detected clothianidin (max = 176 ppb), imidacloprid (max = 141 ppb), and acetamiprid (max = 7 ppb) in soil samples. In water samples, we detected clothianidin (max = 0.67 ppb), imidacloprid (max = 0.18 ppb), and thiamethoxam (max = 2

  5. Effects of clothianidin on aquatic communities: Evaluating the impacts of lethal and sublethal exposure to neonicotinoids.

    Directory of Open Access Journals (Sweden)

    Jesse C Miles

    Full Text Available The widespread usage of neonicotinoid insecticides has sparked concern over their effects on non-target organisms. While research has largely focused on terrestrial systems, the low soil binding and high water solubility of neonicotinoids, paired with their extensive use on the landscape, puts aquatic environments at high risk for contamination via runoff events. We assessed the potential threat of these compounds to wetland communities using a combination of field surveys and experimental exposures including concentrations that are representative of what invertebrates experience in the field. In laboratory toxicity experiments, LC50 values ranged from 0.002 ppm to 1.2 ppm for aquatic invertebrates exposed to clothianidin. However, freshwater snails and amphibian larvae showed high tolerance to the chemical with no mortality observed at the highest dissolvable concentration of the insecticide. We also observed behavioral effects of clothianidin. Water bugs, Belostoma flumineum, displayed a dose-dependent reduction in feeding rate following exposure to clothianidin. Similarly, crayfish, Orconectes propinquus, exhibited reduced responsiveness to stimulus with increasing clothianidin concentration. Using a semi-natural mesocosm experiment, we manipulated clothianidin concentration (0.6, 5, and 352 ppb and the presence of predatory invertebrates to explore community-level effects. We observed high invertebrate predator mortality with increases in clothianidin concentration. With increased predator mortality, prey survival increased by 50% at the highest clothianidin concentration. Thus, clothianidin contamination can result in a top-down trophic cascade in a community dominated by invertebrate predators. In our Indiana field study, we detected clothianidin (max = 176 ppb, imidacloprid (max = 141 ppb, and acetamiprid (max = 7 ppb in soil samples. In water samples, we detected clothianidin (max = 0.67 ppb, imidacloprid (max = 0.18 ppb, and

  6. Lethal and sub-lethal chronic effects of the herbicide diuron on seagrass.

    Science.gov (United States)

    Negri, Andrew P; Flores, Florita; Mercurio, Phil; Mueller, Jochen F; Collier, Catherine J

    2015-08-01

    Photosystem II herbicides from agricultural sources have been detected throughout nearshore tropical habitats including seagrass meadows. While PSII herbicides have been shown to inhibit growth in microalgae at low concentrations, the potential impacts of chronic low concentration exposures to seagrass health and growth have not been investigated. Here we exposed two tropical seagrass species Halodule uninervis and Zostera muelleri to elevated diuron concentrations (from 0.3 to 7.2μgl(-1)) over a 79-day period followed by a 2-week recovery period in uncontaminated seawater. PAM fluorometry demonstrated rapid effect of diuron on photosystem II (PSII) in both seagrass species at 0.3μgl(-1). This effect included significant inhibition of photosynthetic efficiency (ΔF/Fm') and inactivation of PSII (Fv/Fm) over the 11 week exposure period. Significant mortality and reductions in growth was only observed at the highest exposure concentration of 7.2μgl(-1) diuron. However, biochemical indicators demonstrated that the health of seagrass after this prolonged exposure was significantly compromised at lower concentrations. For example, the drop in C:N ratios (0.6μgl(-1)) and reduced δ(13)C (1.7μgl(-1)) in seagrass leaves indicated reduced C-assimilation from photosynthesis. Critically, the energetic reserves of the plants (as measured by starch content in the root-rhizome complex) were approximately halved following diuron exposure at and above 1.7μgl(-1). During the 2-week recovery period, the photosynthetic capacity of the seagrass improved with only plants from the highest diuron treatment still exhibiting chronic damage to PSII. This study shows that, although seagrass may survive prolonged herbicide exposures, concentrations ≥0.6μgl(-1) diuron equivalents cause measureable impacts on energetic status that may leave the plants vulnerable to other simultaneous stressors. For example, tropical seagrasses have been heavily impacted by reduced light from coastal

  7. Lethal and sublethal effects of neem on Aphis gossypii and Cycloneda sanguinea in watermelon

    Directory of Open Access Journals (Sweden)

    Cíntia Ribeiro Souza

    2015-05-01

    Full Text Available The objective of this study was to evaluate the impact of oil extract of neem, Azadirachta indica, on the watermelon aphid Aphis gossypii and its natural enemy Cycloneda sanguinea. Toxicity bioassays were conducted with the commercial product DalNeem (1,475 g L-1 azadirachtin at 0.0037 µg a.i. mL-1, 0.0074 µg a.i. mL-1 and 0.0148 µg a.i. mL-1, Malathion at 1 µg a.i. mL-1 and distilled water as a control treatment. The products were sprayed to watermelon leaf discs, and the insects were exposed to the product residues. The instantaneous population growth rate of A. gossypii and the survival of C. sanguinea larvae exposed to the different treatments were calculated. A decrease in the instantaneous population growth rate of A. gossypii with increasing concentrations of neem was observed, and the aphids did not reproduce on the leaf discs treated with malathion during the first 24 hours of exposure due to its rapid lethal effect on adult insects. The larvae of the predator C. sanguinea exposed to malathion survived only for 24 hours. The survival of the predator exposed to different concentrations of neem was also significantly reduced compared to the predators exposed only to water. However, laboratory experiments may overestimate the effect of neem on predators because the individuals cannot employ escape behavior caused by neem repellency.

  8. Fate and sublethal effects of isoproturon on mature earthworm (Lumbricus terrestris L.).

    Science.gov (United States)

    Mosleh, Y Y; Paris-Palacios, S; Couderchet, M; Vernet, G

    2002-01-01

    This study was conducted to investigate the effects of isoproturon in mature earthworm (Lumbricus terrestris L.) under laboratory condition. Earthworms were exposed to soils contaminated with different concentrations for various duration. Residues were monitored in soil and earthworms after 7, 15, 30, 45, and 60 days of exposure to different isoproturon concentrations. Acute toxicity of isoproturon was determined together with growth rate and total soluble protein content of worms. These parameters were related to isoproturon concentration in soil and earthworms. No lethal effect of isoproturon was observed even at the highest concentration tested (1.4 g/kg soil) after 60 days after treatment. Residues of isoproturon have caused a significant reduction of the growth rate. Additionally a reduction of total soluble protein was observed in all treated worms. Decrease of isoproturon concentration in soil was slow and depended on herbicide initial concentration. In the worms, it increased during the first 15 days and decreased thereafter. This study is suggesting the use of the growth rate of earthworms as biomarker of exposure to isoproturon.

  9. Sublethal effects in Atlantic salmon (Salmo salar) exposed to mixtures of copper, aluminium and gamma radiation

    International Nuclear Information System (INIS)

    Heier, Lene Sørlie; Teien, Hans Christian; Oughton, Deborah; Tollefsen, Knut-Erik; Olsvik, Pål A.; Rosseland, Bjørn Olav; Lind, Ole Christian; Farmen, Eivind; Skipperud, Lindis; Salbu, Brit

    2013-01-01

    The present study was designed to investigate the effects in presmolt of Atlantic salmon (Salmo salar) exposed to copper (Cu), aluminium (Al) and gamma radiation, individually or in combination. Fish were exposed for 48 h to metals added to lake water; 10, 40 and 80 μg Cu/L, 250 μg Al/L and a combination of 40 μg Cu/L and 250 μg Al/L. In addition, gamma radiation (4–70 mGy delivered over 48 h) was added as an additional exposure stressor. Selected endpoints were chosen to reveal different toxic mechanisms and included Cu and Al accumulation on gills, blood chemistry and haematological variables (plasma sodium and chloride, haematocrit, glucose), hepatic levels of reduced and oxidised glutathione (GSH and GSSG) and hepatic transcriptional response of glutathione peroxidase (GPx), gamma-glutamylcysteine synthetase (GCS), metallothionein (MT) and ubiquitin. Exposure to Cu alone resulted in gill accumulation of Cu, reduction of plasma ions and increased transcriptional response of GPx, MT and ubiquitin. Exposure to Al alone reduced plasma ion levels but did not affect any of the hepatic biomarkers except for ubiquitin. The combined metal exposure (Cu + Al) altered the GSH levels, however GPx and MT were not affected suggesting a different mode of detoxification in the combined exposure. Gamma radiation appeared to influence GSH and ubiquitin levels. The observed effects seemed to be both stressor and concentration dependent

  10. Sublethal Growth Effects and Mortality to Marine Bivalves and Fish from Long-Term Exposure to Tributyltin.

    Science.gov (United States)

    1985-07-01

    sublethal toxicity of tributyltin oxide (TBTO) and its putative environmental product, tribu- tyltin sulfide ( TBTS ) to zoeal mud crabs, RIthropanopeus...Organotin .,’vwfuf coatingsu~~ study better defines the longterm toxicity and bloaccumnulation potential of tributyltin released from antifouting...larval fish survival at low tributyltin concentrations were also tested. Acute toxicity tests (96 hours) were con- ducted with mysid shrmp (Aawhomyot

  11. Effect of sublethal concentrations of zinc on reproduction in the zebrafish, Brachydanio rerio Hamilton--Buchanan

    Energy Technology Data Exchange (ETDEWEB)

    Speranza, A.W.; Seeley, R.J.; Seeley, V.A.; Perlmutter, A.

    1977-03-01

    Adult zebrafish, when held in water containing a threshold concentration (55 ppM) of zinc for a 9-day period in which the gametes were maturing, showed a delay in spawning. When spawning did occur, the experimental pairs of fish produced an average of 165 eggs of which only 21.1 percent were viable. In contrast, control pairs of fish produced an average of 434 eggs of which 90.2 percent were viable. In addition, survival of the eggs to hatching was significantly lower than in controls, the survival rate for the experimentals being 0.9 percent, that of the controls, 63.3 percent. The adverse effects on zebrafish of exposure to zinc can be reversed by returning the fish to a zinc-free environment.

  12. Lethal and sub-lethal chronic effects of the herbicide diuron on seagrass

    Energy Technology Data Exchange (ETDEWEB)

    Negri, Andrew P., E-mail: a.negri@aims.gov.au [Australian Institute of Marine Science, Townsville, Queensland 4810 (Australia); Flores, Florita [Australian Institute of Marine Science, Townsville, Queensland 4810 (Australia); Mercurio, Phil [Australian Institute of Marine Science, Townsville, Queensland 4810 (Australia); University of Queensland and National Research Centre for Environmental Toxicology, Coopers Plains, Queensland 4108 (Australia); Mueller, Jochen F. [University of Queensland and National Research Centre for Environmental Toxicology, Coopers Plains, Queensland 4108 (Australia); Collier, Catherine J. [Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University, Cairns, Queensland 4870 (Australia)

    2015-08-15

    Highlights: • We performed chronic exposures of two seagrass species to the herbicide diuron. • Diuron affected photosystem II (PSII) at 0.3 μg l{sup −1} and growth at 7.2 μg l{sup −1}. • Biomarkers indicated that carbon-assimilation from photosynthesis dropped following 0.6 μg l{sup −1} diuron exposure. • Energetic reserves in the seagrass were halved at 1.7 μg l{sup −1} after 11 weeks. • Chronic exposure to diuron is likely to enhance the impacts of low light stress during flood plumes - Abstract: Photosystem II herbicides from agricultural sources have been detected throughout nearshore tropical habitats including seagrass meadows. While PSII herbicides have been shown to inhibit growth in microalgae at low concentrations, the potential impacts of chronic low concentration exposures to seagrass health and growth have not been investigated. Here we exposed two tropical seagrass species Halodule uninervis and Zostera muelleri to elevated diuron concentrations (from 0.3 to 7.2 μg l{sup −1}) over a 79-day period followed by a 2-week recovery period in uncontaminated seawater. PAM fluorometry demonstrated rapid effect of diuron on photosystem II (PSII) in both seagrass species at 0.3 μg l{sup −1}. This effect included significant inhibition of photosynthetic efficiency (ΔF/F{sub m}′) and inactivation of PSII (F{sub v}/F{sub m}) over the 11 week exposure period. Significant mortality and reductions in growth was only observed at the highest exposure concentration of 7.2 μg l{sup −1} diuron. However, biochemical indicators demonstrated that the health of seagrass after this prolonged exposure was significantly compromised at lower concentrations. For example, the drop in C:N ratios (0.6 μg l{sup −1}) and reduced δ{sup 13}C (1.7 μg l{sup −1}) in seagrass leaves indicated reduced C-assimilation from photosynthesis. Critically, the energetic reserves of the plants (as measured by starch content in the root-rhizome complex) were

  13. Lethal and sub-lethal chronic effects of the herbicide diuron on seagrass

    International Nuclear Information System (INIS)

    Negri, Andrew P.; Flores, Florita; Mercurio, Phil; Mueller, Jochen F.; Collier, Catherine J.

    2015-01-01

    Highlights: • We performed chronic exposures of two seagrass species to the herbicide diuron. • Diuron affected photosystem II (PSII) at 0.3 μg l −1 and growth at 7.2 μg l −1 . • Biomarkers indicated that carbon-assimilation from photosynthesis dropped following 0.6 μg l −1 diuron exposure. • Energetic reserves in the seagrass were halved at 1.7 μg l −1 after 11 weeks. • Chronic exposure to diuron is likely to enhance the impacts of low light stress during flood plumes - Abstract: Photosystem II herbicides from agricultural sources have been detected throughout nearshore tropical habitats including seagrass meadows. While PSII herbicides have been shown to inhibit growth in microalgae at low concentrations, the potential impacts of chronic low concentration exposures to seagrass health and growth have not been investigated. Here we exposed two tropical seagrass species Halodule uninervis and Zostera muelleri to elevated diuron concentrations (from 0.3 to 7.2 μg l −1 ) over a 79-day period followed by a 2-week recovery period in uncontaminated seawater. PAM fluorometry demonstrated rapid effect of diuron on photosystem II (PSII) in both seagrass species at 0.3 μg l −1 . This effect included significant inhibition of photosynthetic efficiency (ΔF/F m ′) and inactivation of PSII (F v /F m ) over the 11 week exposure period. Significant mortality and reductions in growth was only observed at the highest exposure concentration of 7.2 μg l −1 diuron. However, biochemical indicators demonstrated that the health of seagrass after this prolonged exposure was significantly compromised at lower concentrations. For example, the drop in C:N ratios (0.6 μg l −1 ) and reduced δ 13 C (1.7 μg l −1 ) in seagrass leaves indicated reduced C-assimilation from photosynthesis. Critically, the energetic reserves of the plants (as measured by starch content in the root-rhizome complex) were approximately halved following diuron exposure at and above

  14. Lethal and sublethal effects, and incomplete clearance of ingested imidacloprid in honey bees (Apis mellifera).

    Science.gov (United States)

    Sánchez-Bayo, Francisco; Belzunces, Luc; Bonmatin, Jean-Marc

    2017-11-01

    A previous study claimed a differential behavioural resilience between spring or summer honey bees (Apis mellifera) and bumble bees (Bombus terrestris) after exposure to syrup contaminated with 125 µg L -1 imidacloprid for 8 days. The authors of that study based their assertion on the lack of body residues and toxic effects in honey bees, whereas bumble bees showed body residues of imidacloprid and impaired locomotion during the exposure. We have reproduced their experiment using winter honey bees subject to the same protocol. After exposure to syrup contaminated with 125 µg L -1 imidacloprid, honey bees experienced high mortality rates (up to 45%), had body residues of imidacloprid in the range 2.7-5.7 ng g -1 and exhibited abnormal behaviours (restless, apathetic, trembling and falling over) that were significantly different from the controls. There was incomplete clearance of the insecticide during the 10-day exposure period. Our results contrast with the findings reported in the previous study for spring or summer honey bees, but are consistent with the results reported for the other bee species.

  15. Acute toxicity and sublethal effects of white phosphorus in mute swans, Cygnus olor

    Science.gov (United States)

    Sparling, D.W.; Day, D.; Klein, P.

    1999-01-01

    Among the waterfowl affected by white phosphorus (P4) at a military base in Alaska are tundra (Cygnus columbianus) and trumpeter (C. buccinator) swans. To estimate the toxicity of P4 to swans and compare the toxic effects to those of mallards (Anas platyrhynchos), we dosed 30 juvenile mute swans (C. olor) with 0 to 5.28 mg P4 /kg body weight. The estimated LD50 was 3.65 mg/kg (95% CI: 1.40 to 4.68 mg/kg). However, many of the swans still had P4 in their gizzards after dying, as determined by 'smoking gizzards', and a lower LD50 might be calculated if all of the P4 had passed into the small intestines. We attribute the retention of P4 in swans to the presence of coarse sandlike particles of grit which were of similar size as the P4 pellets. Most swans took 1 to 4.5 days to die in contrast to the few hours normally required in mallards and death appeared to related more to liver dysfunction than to hemolysis. White phosphorus affected several plasma constituents, most notably elevated aspartate amiontransferase, blood urea nitrogen, lactate dehydrogenase, and alanine aminotransferase.

  16. Synergistic sub-lethal effects of a biocide mixture on the springtail Folsomia fimetaria

    International Nuclear Information System (INIS)

    Schnug, Lisbeth; Leinaas, Hans Petter; Jensen, John

    2014-01-01

    The toxicity of three biocides, esfenvalerate, picoxystrobin and triclosan, on adult survival and recruitment of juveniles was studied in the springtail Folsomia fimetaria, both in single and mixture experiments. Recruitment of juveniles was more sensitive to biocide exposure than adult survival. The concepts of concentration addition and independent action returned almost identical toxicity predictions, though both models failed to predict the observed toxicity due to synergistic deviations at high exposure concentrations. A comparison with a similar study on earthworms showed that response-patterns were species-specific. Consequently, there is no single reference concept which is applicable for all species of one ecosystem, which in turn questions the usefulness of such mixture prediction concepts in ecological risk assessment. -- Highlights: • Toxicity of esfenvalerate, picoxystrobin and triclosan to Folsomia fimetaria was assessed. • Both, the single biocides and the mixture affected recruitment stronger than survival. • Concentration addition and independent action predictions were almost identical. • Inhibition of recruitment after mixture exposure was stronger than predicted. • Comparison with an earthworm study showed that responses are species-specific. -- The concepts of concentration addition and independent action failed to predict mixture toxicity due to dose-dependent synergistic effects

  17. Biological Effects of Ionizing Radiation

    Science.gov (United States)

    Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.

    1952-04-07

    This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.

  18. The effect of sub-lethal doses on the ploidy level in rats hepatocytes with aging

    International Nuclear Information System (INIS)

    Ekhtiar, A. M.

    2004-11-01

    It has been shown that the polyploidization levels in rat's hepatocytes increased with aging. The high LET ionizing radiation also induce cell polyploidization by two different means: cells and nuclei fusion, and mitosis restriction after DNA replication. The purpose of the present study was to determine the kinetic of rat's hepatocytes polyploidization with ageing, and the late effects of low doses of gamma irradiation on polyploidization. To this end, three groups of rats were used. Each group composed of 175 four weeks old animals. The first was served as a control, the second and the third groups were irradiated with 4 and 2 Gy respectively, of gamma irradiation at the age of one month. Of each group, 7-8 animals were monthly scarified (for two years), and their liver tissues were used to obtain cell suspensions which were further fixed in gradual series concentrations of ethanol. After staining with Propidum Iodide 'PI' (10 6 cells per ml of PI used at 10 - 5 M final concentration), the cells were analyzed on a FACS Vantage Flow Cytometer (Becton Dickinson). In the control, the results showed: 1) A decrease of cell fraction that contained normal diploid until steady level. 2) Biphasic changes of fraction tetraploidy cells (increase until age of 4 month followed by decrease). 3) The fraction of octaploidy cells appeared at age of 3-4 month and increased continuously with the aging. In accompanied to life-span reductions of 4 Gy irradiated animals, the DNA contents were similar to those in control groups in addition to some quantities variation due to a programmed cell death (Apoptosis) induced by irradiation and regenerations. These variations persisted till the age of 7 month, in additional to reduce the spin-life of irradiated animals. The irradiation with 2 Gy induced some quantities variation in comparison with nonirradiated group, appeared in the reduction of rate conversion from one ploidy class to another, and in shift with 2-3 months of the second pike

  19. Linking sub-individual and supra-individual effects in Daphnia magna exposed to sub-lethal concentration of chlorpyrifos.

    Science.gov (United States)

    Ferrario, Claudia; Parolini, Marco; De Felice, Beatrice; Villa, Sara; Finizio, Antonio

    2018-04-01

    The main objective of the present study was to investigate possible links between sub-individual and supra-individual levels (i.e. population level) biomarkers in D. magna exposed to sublethal concentrations of the insecticide chlorpyrifos (CPF). To achieve the aim, 8-day old individuals were exposed for 96 h to two environmentally relevant concentrations of CPF (50 and 250 ng/L). Sub-individual level effects were investigated by measuring the activity of antioxidant (SOD, CAT, and GPx) and detoxifying (GST) enzymes, as well as by measuring the acetylcholinesterase (AChE) inhibition. In addition, the effects at supra-individual level were assessed by using a video-tracking system and analyzing changes in swimming capabilities (i.e. percentage of activity time, distance moved, and velocity). Our data have shown that daphnids exposed to both CPF concentrations were in a condition of stress which was highlighted by changes in both sub- and supra-individual biomarkers. Moreover, our results highlighted that the lowest tested CPF concentration did not modulate the antioxidant and detoxifying enzymes, whereas, an inhibition of AChE and a decrease of some parameters related to swimming behaviour (distance moved and velocity) were noted. On the contrary, significant changes in all the sub-individual biomarkers were measured at the highest tested concentration. In addition, organisms recovered the movement capability (distance moved) and also activate a mechanism of avoidance (increased swimming velocity). On the other hand, a reduction in the percent of active time was measured and this was attributed to the energy spent by organisms to activate antioxidant and detoxifying enzymes and the mechanism of avoidance. Based on these results, our study suggests the existence of a link between sub- and supra-individual levels, as the activation or non-activation in the antioxidant and detoxifying enzymes activities can led to different modifications of the swimming behaviour

  20. Sublethal effects of four insecticides on folding and spinning behavior in the rice leaffolder, Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Yang, Yajun; Wang, Caiyun; Xu, Hongxing; Lu, Zhongxian

    2018-03-01

    The rice leaffolder, Cnaphalocrocis medinalis, is an important rice pest. The sublethal effects of chlorpyrifos, chlorantraniliprole, emamectin benzoate and spinosad were investigated on the folding and spinning behaviors of third- to fifth-instar C. medinalis larvae (L3 - L5) after insecticidal exposure of the second instar. A 25% lethal concentration (LC 25 ) of chlorpyrifos prolonged the leaf selection time of L5, and reduced the number of binds per primary fold for L4 and L5. An LC 10 of chlorantraniliprole reduced the number of binds per primary fold for L4 and increased the number of head swings per bind for L5. An LC 10 of emamectin benzoate shortened the primary fold length for L5 and decreased the number of head swings per primary fold for L3 and L4 and the number of head swings per bind for L3, while an LC 25 of emamectin benzoate shortened the fold length per 24 h for L5 and folding time for L3. An LC 10 of spinosad lowered the fold length per 24 h and the number of head swings for L5. An LC 25 of spinosad prolonged leaf selection time, and decreased primary fold length, binds per primary fold, binds per fold and fold length per 24 h in L5. Emamectin benzoate and spinosad exerted stronger sublethal effects on the folding and spinning behavior of C. medinalis than chlorpyrifos and chlorantraniliprole. These results provide better understanding of the sublethal effects of interactions of insecticides on C. medinalis. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  1. Biodiversity of soil bacteria exposed to sub-lethal concentrations of phosphonium-based ionic liquids: Effects of toxicity and biodegradation

    DEFF Research Database (Denmark)

    Sydow, Mateusz; Owsianiak, Mikołaj; Framski, Grzegorz

    2018-01-01

    on the structure of microbial community present in an urban park soil in 100-day microcosm experiments. The biodiversity decreased in all samples (Shannon's index decreased from 1.75 down to 0.74 and OTU's number decreased from 1399 down to 965) with the largest decrease observed in the microcosms spiked with ILs...... ILs or their metabolites. Thus, the introduction of phosphonium-based ILs into soils at sub-lethal concentrations may result not only in a decrease in biodiversity due to toxic effects, but also in enrichment with ILs-degrading bacteria....

  2. Effects of sub-lethal neurite outgrowth inhibitory concentrations of chlorpyrifos oxon on cytoskeletal proteins and acetylcholinesterase in differentiating N2a cells

    Energy Technology Data Exchange (ETDEWEB)

    Flaskos, J., E-mail: flaskos@vet.auth.gr [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Nikolaidis, E. [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Harris, W. [School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom); Sachana, M. [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Hargreaves, A.J., E-mail: alan.hargreaves@ntu.ac.uk [School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom)

    2011-11-15

    Previous work in our laboratory has shown that sub-lethal concentrations (1-10 {mu}M) of chlorpyrifos (CPF), diazinon (DZ) and diazinon oxon (DZO) inhibit the outgrowth of axon-like neurites in differentiating mouse N2a neuroblastoma cells concomitant with altered levels and/or phosphorylation state of axonal cytoskeleton and growth-associated proteins. The aim of the present work was to determine whether chlorpyrifos oxon (CPO) was capable of inhibiting N2a cell differentiation in a similar manner. Using experimental conditions similar to our previous work, sub-lethal concentrations (1-10 {mu}M) of CPO were found to inhibit N2a cell differentiation. However, unlike previous studies with DZ and DZO, there was a high level of sustained inhibition of acetylcholinesterase (AChE) in CPO treated cells. Impairment of neurite outgrowth was also associated with reduced levels of growth associated protein-43 and neurofilament heavy chain (NFH), and the distribution of NFH in cells stained by indirect immunofluorescence was disrupted. However, in contrast to previous findings for DZO, the absolute level of phosphorylated NFH was unaffected by CPO exposure. Taken together, the findings suggest that sub-lethal concentrations of CPO inhibit axon outgrowth in differentiating N2a cells and that this effect involves reduced levels of two proteins that play key roles in axon outgrowth and maintenance. Although the inhibition of neurite outgrowth is unlikely to involve AChE inhibition directly, further work will help to determine whether the persistent inhibition of AChE by CPO can account for the different effects induced by CPO and DZO on the levels of total and phosphorylated NFH. -- Highlights: Black-Right-Pointing-Pointer Sub-lethal levels of chlorpyrifos oxon inhibit neurite outgrowth in N2a cells Black-Right-Pointing-Pointer Acetylcholinesterase exhibits sustained inhibition throughout exposure Black-Right-Pointing-Pointer The levels of neurofilament heavy chain and GAP-43

  3. Effects of sub-lethal neurite outgrowth inhibitory concentrations of chlorpyrifos oxon on cytoskeletal proteins and acetylcholinesterase in differentiating N2a cells

    International Nuclear Information System (INIS)

    Flaskos, J.; Nikolaidis, E.; Harris, W.; Sachana, M.; Hargreaves, A.J.

    2011-01-01

    Previous work in our laboratory has shown that sub-lethal concentrations (1–10 μM) of chlorpyrifos (CPF), diazinon (DZ) and diazinon oxon (DZO) inhibit the outgrowth of axon-like neurites in differentiating mouse N2a neuroblastoma cells concomitant with altered levels and/or phosphorylation state of axonal cytoskeleton and growth-associated proteins. The aim of the present work was to determine whether chlorpyrifos oxon (CPO) was capable of inhibiting N2a cell differentiation in a similar manner. Using experimental conditions similar to our previous work, sub-lethal concentrations (1–10 μM) of CPO were found to inhibit N2a cell differentiation. However, unlike previous studies with DZ and DZO, there was a high level of sustained inhibition of acetylcholinesterase (AChE) in CPO treated cells. Impairment of neurite outgrowth was also associated with reduced levels of growth associated protein-43 and neurofilament heavy chain (NFH), and the distribution of NFH in cells stained by indirect immunofluorescence was disrupted. However, in contrast to previous findings for DZO, the absolute level of phosphorylated NFH was unaffected by CPO exposure. Taken together, the findings suggest that sub-lethal concentrations of CPO inhibit axon outgrowth in differentiating N2a cells and that this effect involves reduced levels of two proteins that play key roles in axon outgrowth and maintenance. Although the inhibition of neurite outgrowth is unlikely to involve AChE inhibition directly, further work will help to determine whether the persistent inhibition of AChE by CPO can account for the different effects induced by CPO and DZO on the levels of total and phosphorylated NFH. -- Highlights: ► Sub-lethal levels of chlorpyrifos oxon inhibit neurite outgrowth in N2a cells ► Acetylcholinesterase exhibits sustained inhibition throughout exposure ► The levels of neurofilament heavy chain and GAP-43 protein are reduced ► Neurofilament heavy chain forms aggregates in cell

  4. Lethal and sublethal effects of methoxyphenozide on the development, survival and reproduction of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

    International Nuclear Information System (INIS)

    Zarate, N.; Diaz, O.; Martinez, A.M.; Figueroa, J.I.; Pineda, S.; Schneider, M.I.; Smagghe, G.; Vinuela, E.; Budia, F.

    2011-01-01

    The lethal and sublethal effects of the ecdysone agonist methoxyphenozide on the fall armyworm, Spodoptera frugiperda (J. E. Smith), were investigated by feeding a methoxyphenozide-treated diet to fifth instars until pupation in doses corresponding to the LC 10 and LC 25 for the compound. Larval mortality reached 8% and 26% in the low and high concentration groups, respectively, on the seventh day of the experiment. A progressive larval mortality of 12% for the LC 10 and 60% for the LC 25 was observed before pupation. Treated larvae exhibited lower pupal weights, higher pupal mortality, presence of deformed pupae, and more deformed adults than untreated larvae. The incorporation of methoxyfenozide into the diet had a significant effect on the timing of larval development. The development period for males and females was about seven days longer than the controls for both concentrations tested. In contrast, the compound affected neither pupae nor adult longevity. Finally, S. frugiperda adults that resulted from fifth instars treated with methoxyfenozide were not affected in their mean cumulative number of eggs laid per female (fecundity), nor percentages of eggs hatched (fertility), or the sex ratio. Our results suggest that the combination of lethal and sublethal effects of methoxyfenozide may have important implications for the population dynamics of the fall armyworm. (author)

  5. Lethal and sublethal effects of methoxyphenozide on the development, survival and reproduction of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

    Energy Technology Data Exchange (ETDEWEB)

    Zarate, N.; Diaz, O. [Universidad Autonoma de San Luis Potosi (Mexico). Facultad de Agronomia; Martinez, A.M.; Figueroa, J.I.; Pineda, S., E-mail: spineda_us@yahoo.co [Universidad Michoacana de San Nicolas de Hidalgo, Tarimbaro, Michoacan (Mexico). Inst. de Investigaciones Agropecuarias y Forestales; Schneider, M.I. [National Council of Scientific and Technical Research (CEPAVE/CCT/CONICET), La Plata (Argentina). Centro de Estudios Parasitologicos y de Vectores. Centro Cientifico Tecnologico; Smagghe, G. [Ghent University, Ghent (Belgium). Faculty of Bioscience Engineering. Lab of Agrozoology; Vinuela, E.; Budia, F. [Escuela Tecnica Superior de Ingenieros Agronomos, Madrid (Spain). Escuela Tecnica Superior de Ingenieros Agronomos. Proteccion de Cultivos

    2011-01-15

    The lethal and sublethal effects of the ecdysone agonist methoxyphenozide on the fall armyworm, Spodoptera frugiperda (J. E. Smith), were investigated by feeding a methoxyphenozide-treated diet to fifth instars until pupation in doses corresponding to the LC{sub 10} and LC{sub 25} for the compound. Larval mortality reached 8% and 26% in the low and high concentration groups, respectively, on the seventh day of the experiment. A progressive larval mortality of 12% for the LC{sub 10} and 60% for the LC{sub 25} was observed before pupation. Treated larvae exhibited lower pupal weights, higher pupal mortality, presence of deformed pupae, and more deformed adults than untreated larvae. The incorporation of methoxyfenozide into the diet had a significant effect on the timing of larval development. The development period for males and females was about seven days longer than the controls for both concentrations tested. In contrast, the compound affected neither pupae nor adult longevity. Finally, S. frugiperda adults that resulted from fifth instars treated with methoxyfenozide were not affected in their mean cumulative number of eggs laid per female (fecundity), nor percentages of eggs hatched (fertility), or the sex ratio. Our results suggest that the combination of lethal and sublethal effects of methoxyfenozide may have important implications for the population dynamics of the fall armyworm. (author)

  6. Biodiversity of soil bacteria exposed to sub-lethal concentrations of phosphonium-based ionic liquids: Effects of toxicity and biodegradation.

    Science.gov (United States)

    Sydow, Mateusz; Owsianiak, Mikołaj; Framski, Grzegorz; Woźniak-Karczewska, Marta; Piotrowska-Cyplik, Agnieszka; Ławniczak, Łukasz; Szulc, Alicja; Zgoła-Grześkowiak, Agnieszka; Heipieper, Hermann J; Chrzanowski, Łukasz

    2018-01-01

    Little is known about the effect of ionic liquids (ILs) on the structure of soil microbial communities and resulting biodiversity. Therefore, we studied the influence of six trihexyl(tetradecyl)phosphonium ILs (with either bromide or various organic anions) at sublethal concentrations on the structure of microbial community present in an urban park soil in 100-day microcosm experiments. The biodiversity decreased in all samples (Shannon's index decreased from 1.75 down to 0.74 and OTU's number decreased from 1399 down to 965) with the largest decrease observed in the microcosms spiked with ILs where biodegradation extent was higher than 80%. (i.e. [P 66614 ][Br] and [P 66614 ][2,4,4]). Despite this general decrease in biodiversity, which can be explained by ecotoxic effect of the ILs, the microbial community in the microcosms was enriched with Gram-negative hydrocarbon-degrading genera e.g. Sphingomonas. It is hypothesized that, in addition to toxicity, the observed decrease in biodiversity and change in the microbial community structure may be explained by the primary biodegradation of the ILs or their metabolites by the mentioned genera, which outcompeted other microorganisms unable to degrade ILs or their metabolites. Thus, the introduction of phosphonium-based ILs into soils at sub-lethal concentrations may result not only in a decrease in biodiversity due to toxic effects, but also in enrichment with ILs-degrading bacteria. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Immunocytoadherence and sublethal irradiation

    International Nuclear Information System (INIS)

    Beaumariage, M.L.; Hiesche, K.; Revesz, L.; Haot, J.

    1975-01-01

    In sublethally irradiated CBA mice, the relative and absolute numbers of spontaneous rosette forming cells against sheep erythrocytes are markedly decreased in bone marrow. The decrease of the absolute number of spontaneous RFC is also important in the spleen in spite of an increase of the RFC relative number above the normal values between the 8th and 12th day after irradiation. The graft of normal bone marrow cells immediately after irradiation or the shielding of a medullary area during irradiation promotes the recovery of the immunocytoadherence capacity of the bone marrow cells but not of the spleen cells [fr

  8. Biological effects of neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Ogiu, Toshiaki; Ohmachi, Yasushi; Ishida, Yuka [National Inst. of Radiological Sciences, Chiba (JP)] [and others

    2003-03-01

    Although the occasion to be exposed to neutrons is rare in our life, except for nuclear accidents like in the critical accident at Tokai-mura in 1999, countermeasures against accident should be always prepared. In the Tokai-mura accident, residents received less than 21 mSv of neutrons and gamma rays. The cancer risks and fetal effects of low doses of neutrons were matters of concern among residents. The purpose of this program is to investigate the relative biological effectiveness (RBE) for leukemias, and thereby to assess risks of neutrons. Animal experiments are planed to obtain the following RBEs: (1) RBE for the induction of leukemias in mice and (2) RBE for effects on fetuses. Cyclotron fast neutrons (10 MeV) and electrostatic accelerator-derived neutrons (2 MeV) are used for exposure in this program. Furthermore, cytological and cytogenetic analyses will be performed. (author)

  9. Lethal and sublethal effects of cantharidin on the life history traits and population parameters of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Khan, Rashid A; Rashid, Maryam; Wang, Dun; Zhang, Ya-Lin

    2014-01-01

    The cotton bollworm, Helicoverpa armigera (Hübner), is a serious and cosmopolitan pest of many economic crops. Its control has not been adequate owing to its resistance to many groups of insecticides. Toxicity of cantharidin on armyworm and diamondback moth has already been reported. However, its toxicity on H. armigera has not been investigated previously. In this study, lethal and sublethal effects of cantharidin on H. armigera under laboratory conditions are reported. Results showed gross abnormalities in the population parameters of H. armigera, ranging from larvae to adults. Reduction in larval weight and wing malformation were observed in the cantharidin-treated population cohort, and higher mortality at the larval, pupal and adult stages was observed in cantharidin-treated H. armigera compared with the control. Moreover, almost 5 times less fecundity was recorded in the treated population cohort. Fertility was also severely affected, and reduction in all population parameters was observed. Cantharidin caused larval mortality and other serious abnormalities in H. armigera population parameters, and therefore may have positive implications for pest management decision-making process. More interestingly, the experiment revealed that cantharidin in sublethal dose mimicked insect growth regulator insecticides. Furthermore, cantharidin could be used as a precursor compound for the synthesis of new analogues and compounds to replace ineffective older compounds. © 2013 Society of Chemical Industry.

  10. Effect of exposure to sublethal concentrations of sodium cyanide on the carbohydrate metabolism of the Indian Major Carp Labeo rohita (Hamilton, 1822

    Directory of Open Access Journals (Sweden)

    Praveen N. Dube

    2013-07-01

    Full Text Available Experiments were designed to study in-vivo effects of sodium cyanide on biochemical endpoints in the freshwater fish Labeo rohita. Fish were exposed to two sublethal concentrations (0.106 and 0.064mg/L for a period of 15 days. Levels of glycogen, pyruvate, lactate and the enzymatic activities of lactate dehydrogenase (LDH, succinate dehydrogenase (SDH, glucose-6-phosphate dehydrogenase (G6PDH, phosphorylase, alkaline phosphatase (ALP, acid phosphatase (AcP were assessed in different tissues (liver, muscle and gills. Result indicated a steady decrease in glycogen, pyruvate, SDH, ALP and AcP activity with a concomitant increase in the lactate, phosphorylase, LDH and G6PD activity in all selected tissues. The alterations in all the above biochemical parameters were significantly (p<0.05 time and dose dependent. In all the above parameters, liver pointing out the intensity of cyanide intoxication compare to muscle and gills. Study revealed change in the metabolic energy by means of altered metabolic profile of the fish. Further, these observations indicated that even sublethal concentrations of sodium cyanide might not be fully devoid of deleterious influence on metabolism in L. rohita.

  11. Biological effects of deuterium - depleted water

    International Nuclear Information System (INIS)

    Stefanescu, I.; Titescu, Gh.; Croitoru, Cornelia; Saros-Rogobete, Irina

    2000-01-01

    Deuterium-depleted water (DDW) is represented by water that has an isotopic content smaller than 145 ppm D/(D + H). DDW production technique consists in the separation of deuterium from water by a continuous distillation process under pressure of about 133.3 mbar. The water used as raw material has a isotopic content of 145 ppm D/(D + H) and can be demineralized water, distillated water or condensed-steam. DDW results as a distillate with an isotopic deuterium content of 15-80 ppm, depending on the level we want to achieve. Beginning with 1996 the Institute of Cryogenics and Isotopic Technologies, DDW producer, co-operated with Romanian specialized institutes for studying the biological effects of DDW. The role of naturally occurring D in living organisms was examined by using DDW instead of natural water. These investigations led to the following conclusions: - DDW caused a tendency towards the increase of the basal tone, accompanied by the intensification of the vasoconstrictor effects of phenylefrine, noradrenaline and angiotensin; the increase of the basal tone and vascular reactivity produced by the DDW persists after the removal of the vascular endothelium; - Animals treated with DDW showed an increase of the resistance both to sublethal and lethal gamma radiation doses, suggesting a radioprotective action by the stimulation of non-specific immune defense mechanisms; - DDW stimulates immuno-defense reactions represented by the opsonic, bactericidal and phagocyte capacity of the immune system together with an increase in the number of poly-morphonuclear neutrophils; - Investigations regarding artificial reproduction of fish with DDW fecundated solutions confirmed favorable influence in embryo growth stage and resistance and following growth stages; - It was studied germination, growth and quantitative character variability in plants; one can remark the favorable influence of DDW on biological processes in plants in various ontogenetic stages. (authors)

  12. Effect of granulocyte colony-stimulating factor on murine thymic emigration and subsets reconstitution after a sublethal dose of irradiation

    International Nuclear Information System (INIS)

    Zhao Hongxia; Guo Mei; Sun Xuedong; Ai Huisheng

    2011-01-01

    Objective: To investigate the effects of recombinant human granulocyte colony stimulating factor (G-CSF) on murine thymic emigration and subsets reconstitution after a sublethal dose of irradiation. Methods: Female BALB/c mice were irradiated with a 6.0 Gy of γ-ray total-body irradiation and then randomly divided into GCSF group and control group. For mice in the GCSF group, recombinant human G-CSF 100 μg · kg -1 · d -1 was injected subcutaneously once daily for 14 continuous days and mice in the control group were given the same volume of phosphate buffered solution (PBS). At 7, 14, 21 and 28 days later, mice were killed and thymus mononuclear cell suspension were analyzed by flow cytometry for the percentage of the four stages of thymic CD4 - CD8 - double negative cells (DN1-4) and the CD4 + CD8 + double positive ( CD4 + CD8 + DP), CD4 + CD8 - single positive (CD4 + SP), CD4 - CD8 + single positive cells (CD8 + SP).Real-time PCR was used for detection and quantitation of murine T cell receptor rearrangement excision circles (sjTRECs) of the thymic cells of 30 and 60 d after irradiation. Results: The percentage of thymic DN1 cells in GCSF group was significantly higher than that of the control group 7 d after irradiation (t=9.59, P<0.05). 21 d later, the proportion of thymic DN3 and DN4 cells were higher than those of the control group (t=16.37, 7.6, P<0.05). The percentage of thymic CD4 + CD8 + DP cells decreased 7 d after irradiation,increased at 14 d, decreased again at 21 days,and then got a permanent recover. The percentage of thymic CD4 + CD8 + DP cells in the GCSF group recovered to normal and was significantly higher than that of the control group 28 days after irradiation (t=12.22, P<0.05). The percentage of thymic CD8 + SP cells of the GCSF group was significantly higher than that of the control group 21 d after irradiation (t=3.77, P<0.05), while G-CSF had no obvious influence on the percentage of the thymic CD4 + SP cells. The sjTRECs copies in the

  13. Radioprotective effects in mice by a single dose of subcutaneous administration of cobaltous chloride post γ-rays irradiation with a sublethal dose

    International Nuclear Information System (INIS)

    Izumo, Yoshiro; Ogata, Hiromitsu

    1993-01-01

    Radioprotective effects were investigated in mice which received subcutaneously a single dose of each inorganic metal: Co, Cu, Rb, Sr, Mo and W 24 hours post irradiation of 60 Co γ-rays with a sublethal dose. The effects were observed in mice injected with Co at an optimum dosage of 20 mg/kg·body weight. Then to elucidate mechanisms of the effects, mice were injected with Co containing the radioactive tracer ( 60 Co) following the radiation exposure, measured elimination of the radioactivity for 7 days, then sacrificed and divided to some tissues and organs. The radioactivity in whole body during this period resulted in a markedly higher retention than that for mice injected with [ 60 Co] alone, as well as liver in the organs. These higher retentions appeared to be related to the radioprotective effects. (author)

  14. Sublethal concentration of H2O2 enhances the protective effect of mesenchymal stem cells in rat model of spinal cord injury.

    Science.gov (United States)

    Rahimi, Asrin; Amiri, Iraj; Roushandeh, Amaneh Mohammadi; Choshali, Zoleikha Golipour; Alizadeh, Zohreh; Artimani, Tayebeh; Afshar, Saeid; Asl, Sara Soleimani

    2018-03-01

    To investigate the effect of H 2 O 2 on the migration and antioxidant defense of mesenchymal stem cells (MSCs) and the neurotrophic effects of H 2 O 2 -treated MSCs on spinal cord injury (SCI). Sublethal concentrations of H 2 O 2 decreased cell migration and expression of CXCR4 and CCR2 as well as Nrf2 expression in MSCs. In the second phase, transplantation of treated and untreated MSCs to SCI caused minor changes in locomotor dysfunction. There was a significantly difference between cell-treated and spinal cord injury groups in expression of BDNF (brain-derived neurotrophic factor). Transplantation of H 2 O 2 -treated cells caused an increase in BDNF expression compared to non-treated cells. Transplantation of H 2 O 2 -treated stem cells may have protective effects against SCI through by increasing neurotrophic factors.

  15. Biological effects of tritium

    International Nuclear Information System (INIS)

    Nieto, M.

    1985-01-01

    The aim of this project is to study the thermal effects on proliferation activity in the intestinal epithelium of the goldfish acclimated at different temperatures (stationary state). The cell division occurs only at certain phases of the circadian cycle when the proliferative activity is synchronized or trained by an environmental factor such as light-dark cycle. Another aspect of the project is the study of the biological effects, non-stochastic, on cell kinetics in animals chronically exposed to low dose rates or tritium and gamma rays from 60 CO, used as a standard radiation. The influence on the accumulated dose per cell and cycle cell in function of the duration of the cell cycle at different acclimation temperatures should be considered. To calculate the risk of tritium contamination from nuclear power plants (radiation exposure), the organic tissue-bond is of decisive importance due to the long turnover of the organic tissue-bond in organisms favouring transport of tritium to other organisms of the ecosystem and to man. (author)

  16. Effects of recombinant human granulocyte colony-stimulating factor on central and peripheral T lymphocyte reconstitution after sublethal irradiation in mice

    International Nuclear Information System (INIS)

    Zhao Hongxia; Guo Mei; Sun Xuedong; Ai Huisheng; Sun Wanjun; Hu Hailan; Wei Li

    2013-01-01

    Granulocyte colony-stimulating factor (G-CSF) is one of the most critical cytokines used for the treatment of acute radiation syndrome (ARS). In addition to the hematopoietic effects of G-CSF on the differentiation and proliferation of myeloid progenitor cells, G-CSF is also known to have immunomodulatory effects. The aim of the present study was to investigate whether G-CSF could accelerate central and peripheral T lymphocyte recovery after a sublethal dose of irradiation. Female BALB/c mice were subjected to 6 Gy of total body irradiation and then were treated with either 100 μg/kg G-CSF or an equal volume of PBS once daily for 14 days. Percentages of thymocyte subpopulations including CD4- CD8-, CD4+ CD8+, CD4+ CD8- and CD4- CD8+ T cells, peripheral CD3+, CD4+ and CD8+ cells were analyzed by flow cytometry. Recent thymic emigrants (RTEs) were assessed by real-time polymerase chain reaction (PCR) using primers specific to the 257-bp T cell receptor rearrangement excision circles (sjTRECs). The proliferative capacity of splenic mononuclear cells upon exposure to ConA was measured by using the Cell Count Kit-8 (CCK-8). G-CSF treatment promoted thymocyte regeneration, accelerated the recovery of CD4+ CD8+ cells and increased the frequency of thymocyte sjTRECs. These effects were more prominent at early time points (Day 28) after irradiation. G-CSF also increased the rate of recovery of peripheral CD3+, CD4+ and CD8+ cells and shortened the period of severe lymphopenia following irradiation. G-CSF also increased the splenic mononuclear cell mitotic responsiveness to ConA more than control-treated cells. Our results show that G-CSF accelerates T cell recovery through both thymic-dependent and thymic-independent pathways, which could be used to increase the rate of immune reconstitution after sublethal irradiation. (author)

  17. Sublethal effects of the Exxon Valdez oil spill on herring embryos and larvae: morphological, cytogenetic; and histopathological assessments, 1989-1991

    International Nuclear Information System (INIS)

    Hose, J. E.; Marty, G. D.; Hinton, D. E.

    1996-01-01

    Extensive sublethal damage assessments were carried out on Pacific herring larvae following the Exxon Valdez oil spill. Egg masses were collected from oiled and non-oiled areas during 1989 to 1991, and incubated to hatch. The hatched larvae were evaluated for morphological deformities, cytogenetic abnormalities, and histopathological lesions. In 1989, herring larvae from the oiled areas showed high incidence of morphological deformities and cytogenetic abnormalities compared to larvae from non-oiled areas. There was no evidence of histopathological lesions. Identical assessments in 1990 and 1991 revealed no detectable oil-related developmental and genetic effects. In contrast, there was a marked decrease in survival, suggesting that that genetic damage at heavily oiled stations combined with severe morphological malformations mitigated against survival through the stressful larval period. 40 refs., 1 tab.,8 figs

  18. Assessing the sublethal effects of in-river concentrations of parameters contributing to cumulative effects in the Athabasca river basin using a fathead minnow bioassay.

    Science.gov (United States)

    Squires, Allison J; Dubé, Monique G; Rozon-Ramilo, Lisa D

    2013-03-01

    The Athabasca River basin, located in Alberta, Canada, covers 157, 000 km(2) and holds significant cultural and economic importance. Recent research assessed changes in several water quality and quantity parameters that have changed both spatially (along the river continuum) and temporally (pre-development and present day) in the Athabasca River Basin. In particular, parameters such as salinity and dissolved sulphate have changed significantly across the Athabasca River mainstem over the past five decades. Further laboratory testing has linked concentrations of these parameters to changes in fathead minnow reproduction. Research is required to determine whether these changes observed in the laboratory can be applied to actual in-river conditions. The objectives of the present study were to twofold: assess changes in fathead minnow response metrics (i.e., condition, liver and gonad size, egg production, and gill histology) associated with increasing concentrations of salinity and dissolved sulphate and determine whether sublethal effect thresholds established in laboratory experiments correspond to actual in-river concentrations using water from the mouth and headwaters of the Athabasca River. Three dose-response experiments (NaCl, SO4, and water sampled from the mouth of the Athabasca River) were conducted at Jasper National Park, Alberta, Canada. Significant increases in mean eggs per female per day occurred at the 50% treatment for the mouth experiment and thresholds previously developed in the laboratory were verified. Copyright © 2012 SETAC.

  19. Effects of sub-lethal high-pressure homogenization treatment on the outermost cellular structures and the volatile-molecule profiles of two strains of probiotic lactobacilli.

    Science.gov (United States)

    Tabanelli, Giulia; Vernocchi, Pamela; Patrignani, Francesca; Del Chierico, Federica; Putignani, Lorenza; Vinderola, Gabriel; Reinheimer, Jorge A; Gardini, Fausto; Lanciotti, Rosalba

    2015-01-01

    Applying sub-lethal levels of high-pressure homogenization (HPH) to lactic acid bacteria has been proposed as a method of enhancing some of their functional properties. Because the principal targets of HPH are the cell-surface structures, the aim of this study was to examine the effect of sub-lethal HPH treatment on the outermost cellular structures and the proteomic profiles of two known probiotic bacterial strains. Moreover, the effect of HPH treatment on the metabolism of probiotic cells within a dairy product during its refrigerated storage was investigated using SPME-GC-MS. Transmission electron microscopy was used to examine the microstructural changes in the outermost cellular structures due to HPH treatment. These alterations may be involved in the changes in some of the technological and functional properties of the strains that were observed after pressure treatment. Moreover, the proteomic profiles of the probiotic strains treated with HPH and incubated at 37°C for various periods showed different peptide patterns compared with those of the untreated cells. In addition, there were differences in the peaks that were observed in the low-mass spectral region (2000-3000 Da) of the spectral profiles of the control and treated samples. Due to pressure treatment, the volatile-molecule profiles of buttermilk inoculated with treated or control cells and stored at 4°C for 30 days exhibited overall changes in the aroma profile and in the production of molecules that improved its sensory profile, although the two different species imparted specific fingerprints to the product. The results of this study will contribute to understanding the changes that occur in the outermost cellular structures and the metabolism of LAB in response to HPH treatment. The findings of this investigation may contribute to elucidating the relationships between these changes and the alterations of the technological and functional properties of LAB induced by pressure treatment.

  20. Biological radiation effects

    International Nuclear Information System (INIS)

    Sejourne, Michele.

    1977-01-01

    This work examines ionizing radiations: what they are, where they come from, their actions and consequences, finally the norms and preventive measures necessary to avoid serious contamination, whether the individual or the population in general is involved. Man has always been exposed to natural irradiation, but owing to the growing use of ionizing radiations both in medicine and in industry, not to mention nuclear tests and their use as an argument of dissuasion, the irradiation of human beings is increasing daily. Radioactive contamination does remain latent, apart from acute cases, but this is where the danger lies since the consequences may not appear until long after the irradiation. Of all biological effects due to the action of radioelements the genetic risk is one of the most important, affecting the entire population and especially the generations to come. The risk of cancer and leukemia induction plays a substantial part also since a large number of people may be concerned, depending on the mode of contamination involved. All these long-term dangers do not of course exclude the various general or local effects to which the individual alone may be exposed and which sometimes constitute a threat to life. As a result the use of ionizing radiations must be limited and should only be involved if no other process can serve instead. The regulations governing radioelements must be stringent and their application strictly supervised for the better protection of man. This protection must be not only individual but also collective since pollution exists in air, water and land passes to plants and animals and finally reaches the last link in the food chain, man [fr

  1. Effects of sublethal gamma radiation on T and B cell activity in the antibody response of mice

    International Nuclear Information System (INIS)

    Carlson, D.E.; Lubet, R.A.

    1976-01-01

    The relative radiosensitivity of T and B cells was followed in sublethally irradiated mice reconstituted with bone marrow cells, thymus cells, or both, and simultaneously challenged with sheep erythrocytes. Numbers of antibody-forming cells in recipient spleens were determined on days 4 to 8. In this assay the response of mice given bone marrow cells was limited by the amount of residual T cell activity, while the response of mice given thymus cells was limited by the residual B cell activity. Although residual activity of both T and B cells was suppressed in mice given 300 to 700 rad at 80 rad/min, residual B cell activity was consistently lower in these animals. When antibody responses were initiated at intervals after irradiation, B cell activity was clearly limiting by 48 hr after 500 or 600 rad. The activity of both T and B cells was sensitive to differences in dose rate between 8 and 80 rad/min. The 4 to 7 fold dose-rate sensitivity of T cells paralleled that of differentially irradiated nonreconstituted mice. In contrast, dose-rate dependence of B cell activity varied from 10- to 20-fold between 8 and 80 rad/min. These results suggest that radiation suppression of antibody responses in mice is highly dependent upon B cell sensitivity, and that dose-rate dependence of the antibody response may be explained in large part by differential sensitivity of B cells

  2. Biological radiation effects

    International Nuclear Information System (INIS)

    Koggl, D.; Dedenkov, A.N.

    1986-01-01

    All nowadays problems of radio biology are considered: types of ionizing radiations, their interaction with material; damage of molecular structures and their reparation; reaction of cells and their recovery from radiation damage; reaction of the whole organism and its separate systems. Particular attention is given to the problems of radiation carcinogenesis and radiation hazard for man

  3. A proteomic evaluation of the effects of the pharmaceuticals diclofenac and gemfibrozil on marine mussels (Mytilus spp.): evidence for chronic sublethal effects on stress-response proteins.

    Science.gov (United States)

    Schmidt, Wiebke; Rainville, Louis-Charles; McEneff, Gillian; Sheehan, David; Quinn, Brian

    2014-03-01

    Human pharmaceuticals (e.g. the lipid regulator gemfibrozil and the non-steroidal anti-inflammatory drug diclofenac) are an emerging environmental threat in the aquatic environment. This study aimed to evaluate sublethal effects of these two commonly found pharmaceuticals on the protein profiles of marine mussels (Mytilus spp.). Mytilus spp. was exposed to environmentally relevant and elevated concentrations (1 and 1000 µg/l respectively) of both drugs for 14 days. In addition, mussels were maintained for seven days post treatment to examine the potential of blue mussels to recover from such an exposure. Differential protein expression signatures (PES) in the digestive gland of mussels were obtained using two-dimensional gel electrophoresis after 7, 14, and 21 days of exposure. Twelve spots were significantly increased or decreased by gemfibrozil and/or diclofenac, seven of which were successfully identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. These proteins were involved in energy metabolism, oxidative stress response, protein folding, and immune responses. Changes in the PES over time suggested that mussels were still experiencing oxidative stress for up to seven days post exposure. In addition, a suite of biomarkers comprising glutathione transferase, lipid peroxidation, and DNA damage were studied. An oxidative stress response was confirmed by biomarker responses. To our knowledge, this is the first investigation using proteomics to assess the potential effects of human pharmaceuticals on a non-target species in an environmentally-relevant model. The successful application of this proteomic approach supports its potential use in pollution biomonitoring and highlights its ability to aid in the discovery of new biomarkers. Copyright © 2013 John Wiley & Sons, Ltd.

  4. Relationship between Sublethal Injury and Inactivation of Yeast Cells by the Combination of Sorbic Acid and Pulsed Electric Fields▿

    OpenAIRE

    Somolinos, M.; García, D.; Condón, S.; Mañas, P.; Pagán, R.

    2007-01-01

    The objective of this study was to investigate the occurrence of sublethal injury after the pulsed-electric-field (PEF) treatment of two yeasts, Dekkera bruxellensis and Saccharomyces cerevisiae, as well as the relation of sublethal injury to the inactivating effect of the combination of PEF and sorbic acid. PEF caused sublethal injury in both yeasts: more than 90% of surviving D. bruxellensis cells and 99% of surviving S. cerevisiae cells were sublethally injured after 50 pulses at 12 kV/cm ...

  5. Sublethal irradiation promotes invasiveness of neuroblastoma cells

    International Nuclear Information System (INIS)

    Schweigerer, Lothar; Rave-Fraenk, Margret; Schmidberger, Heinz; Hecht, Monica

    2005-01-01

    Neuroblastoma is the most frequent extracranial solid tumour of childhood. Despite multiple clinical efforts, clinical outcome has remained poor. Neuroblastoma is considered to be radiosensitive, but some clinical studies including the German trial NB90 failed to show a clinical benefit of radiation therapy. The mechanisms underlying this apparent discrepancy are still unclear. We have therefore investigated the effects of radiation on neuroblastoma cell behaviour in vitro. We show that sublethal doses of irradiation up-regulated the expression of the hepatocyte growth factor (HGF) and its receptor c-Met in some neuroblastoma cell lines. The increase in HGF/c-Met expression was correlated with enhanced invasiveness and activation of proteases degrading the extracellular matrix. Thus, irradiation at sublethal doses may promote the metastatic dissemination of neuroblastoma cells through activating the HGF/c-Met pathway and triggering matrix degradation

  6. Quantum Effects in Biological Systems

    CERN Document Server

    2016-01-01

    Since the last decade the study of quantum mechanical phenomena in biological systems has become a vibrant field of research. Initially sparked by evidence of quantum effects in energy transport that is instrumental for photosynthesis, quantum biology asks the question of how methods and models from quantum theory can help us to understand fundamental mechanisms in living organisms. This approach entails a paradigm change challenging the related disciplines: The successful framework of quantum theory is taken out of its low-temperature, microscopic regimes and applied to hot and dense macroscopic environments, thereby extending the toolbox of biology and biochemistry at the same time. The Quantum Effects in Biological Systems conference is a platform for researchers from biology, chemistry and physics to present and discuss the latest developments in the field of quantum biology. After meetings in Lisbon (2009), Harvard (2010), Ulm (2011), Berkeley (2012), Vienna (2013), Singapore (2014) and Florence (2015),...

  7. Biology of ionizing radiation effects

    International Nuclear Information System (INIS)

    Ferradini, C.; Pucheault, J.

    1983-01-01

    The present trends in biology of ionizing radiation are reviewed. The following topics are investigated: interaction of ionizing radiations with matter; the radiolysis of water and aqueous solutions; properties of the free radicals intervening in the couples O 2 /H 2 O and H 2 O/H 2 ; radiation chemistry of biological compounds; biological effects of ionizing radiations; biochemical mechanisms involving free radicals as intermediates; applications (biotechnological applications, origins of life) [fr

  8. Biological Effectiveness of Antiproton Annihilation

    DEFF Research Database (Denmark)

    Maggiore, C.; Agazaryan, N.; Bassler, N.

    2004-01-01

    from the annihilation of antiprotons produce an increase in ‘‘biological dose’’ in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct measurement of the biological effects of antiproton annihilation. The background, description, and status...

  9. Sublethal effects of herbicides on the biomass and seed production of terrestrial non-crop plant species, influenced by environment, development stage and assessment date

    International Nuclear Information System (INIS)

    Riemens, Marleen M.; Dueck, Thom; Kempenaar, Corne; Lotz, Lambertus A.P.; Kropff, Martin J.J.

    2009-01-01

    Guidelines provided by the OECD and EPPO allow the use of single-species tests performed in greenhouses to assess the risk of herbicides to non-target terrestrial plant communities in the field. The present study was undertaken to investigate the use of greenhouse data to determine effects of herbicides with a different mode of action on the biomass, seed production and emergence of field-grown plants. In addition, a single species approach was compared with a mixed species approach. Effects on the biomass of greenhouse and field-grown plants were found to be related at different effect levels, indicating that it might be possible to translate results from greenhouse studies to field situations. However, the use of single-species tests may not be valid. The response of a single plant species to sublethal herbicide dosages differed to the response of the same species grown in a mixture with other species. - The use of single-species greenhouse tests in the ecological risk assessment of crop protection products may only be valid for single species in the field, not for vegetations.

  10. Biological effectiveness of high-energy protons - Target fragmentation

    International Nuclear Information System (INIS)

    Cucinotta, F.A.; Katz, R.; Wilson, J.W.; Townsend, L.W.; Shinn, J.; Hajnal, F.

    1991-01-01

    High-energy protons traversing tissue produce local sources of high-linear-energy-transfer ions through nuclear fragmentation. The contribution of these target fragments to the biological effectiveness of high-energy protons using the cellular track model is examined. The effects of secondary ions are treated in terms of the production collision density using energy-dependent parameters from a high-energy fragmentation model. Calculations for mammalian cell cultures show that at high dose, at which intertrack effects become important, protons deliver damage similar to that produced by gamma rays, and with fragmentation the relative biological effectiveness (RBE) of protons increases moderately from unity. At low dose, where sublethal damage is unimportant, the contribution from target fragments dominates, causing the proton effectiveness to be very different from that of gamma rays with a strongly fluence-dependent RBE. At high energies, the nuclear fragmentation cross sections become independent of energy. This leads to a plateau in the proton single-particle-action cross section, below 1 keV/micron, since the target fragments dominate. 29 refs

  11. Biological radiation effects

    International Nuclear Information System (INIS)

    Gomes, R.A.

    1976-01-01

    The stages of processes leading to radiation damage are studied, as well as, the direct and indirect mechanics of its production. The radiation effects on nucleic acid and protein macro moleculas are treated. The physical and chemical factors that modify radiosensibility are analysed, in particular the oxygen effects, the sensibilization by analogues of nitrogen bases, post-effects, chemical protection and inherent cell factors. Consideration is given to restoration processes by excision of injured fragments, the bloching of the excision restoration processes, the restoration of lesions caused by ionizing radiations and to the restoration by genetic recombination. Referring to somatic effects of radiation, the early ones and the acute syndrome of radiation are discussed. The difference of radiosensibility observed in mammalian cells and main observable alterations in tissues and organs are commented. Referring to delayed radiation effects, carcinogeneses, alterations of life span, effects on growth and development, as well as localized effects, are also discussed [pt

  12. Biological effects of particle radiation

    International Nuclear Information System (INIS)

    Sakamoto, Kiyohiko

    1988-01-01

    Conventional radiations such as photons, gamma rays or electrons show several physical or biological disadvantages to bring tumors to cure, therefore, more and more attentions is being paid to new modalitie such as fast neutrons, protons, negative pions and heavy ions, which are expected to overcome some of the defects of the conventional radiations. Except for fast neutrons, these particle radiations show excellet physical dose localization in tissue, moreover, in terms of biological effects, they demonstrate several features compared to conventional radiations, namely low oxygen enhancement ratio, high value of relative biological effectiveness, smaller cellular recovery, larger therapeutic gain factor and less cell cycle dependency in radiation sensitivity. In present paper the biological effects of particle radiations are shown comparing to the effects of conventional radiations. (author)

  13. Identification of water soluble and particle bound compounds causing sublethal toxic effects. A field study on sediments affected by a chlor-alkali industry

    International Nuclear Information System (INIS)

    Bosch, Carme; Olivares, Alba; Faria, Melissa; Navas, Jose M.; Olmo, Ivan del; Grimalt, Joan O.; Pina, Benjamin; Barata, Carlos

    2009-01-01

    A combination of cost effective sublethal Daphnia magna feeding tests, yeast- and cell culture-based bioassays and Toxicity Identification Evaluation (TIE) procedures was used to characterize toxic compounds within sediments collected in a river area under the influence of the effluents from a chlor-alkali industry (Ebro River, NE Spain). Tests were designed to measure and identify toxic compounds in the particulate and filtered water fractions of sediment elutriates. The combined use of bioassays responding to elutriates and dioxin-like compounds evidenced the existence of three major groups of hazardous contaminants in the most contaminated site: (A) metals such as cadmium and mercury bound to sediment fine particles that could be easily resuspended and moved downstream, (B) soluble compounds (presumably, lye) able to alkalinize water to toxic levels, and (C) organochlorine compounds with high dioxin-like activity. These results provided evidence that elutriate D. magna feeding responses can be used as surrogate assays for more tedious chronic whole sediment tests, and that the incorporation of such tests in sediment TIE procedures may improve the ability to identify the toxicity of particle-bound and water-soluble contaminants in sediments.

  14. Proteomic analysis of differentiating neuroblastoma cells treated with sub-lethal neurite inhibitory concentrations of diazinon: Identification of novel biomarkers of effect

    International Nuclear Information System (INIS)

    Harris, W.; Sachana, M.; Flaskos, J.; Hargreaves, A.J.

    2009-01-01

    In previous work we showed that sub-lethal levels of diazinon inhibited neurite outgrowth in differentiating N2a neuroblastoma cells. Western blotting analysis targeted at proteins involved in axon growth and stress responses, revealed that such exposure led to a reduction in the levels of neurofilament heavy chain, microtubule associated protein 1 B (MAP 1B) and HSP-70. The aim of this study was to apply the approach of 2 dimensional polyacrylamide gel electrophoresis and mass spectrometry to identify novel biomarkers of effect. A number of proteins were found to be up-regulated compared to the control on silver-stained gels. These were classified in to 3 main groups of proteins: cytosolic factors, chaperones and the actin-binding protein cofilin, all of which are involved in cell differentiation, survival or metabolism. The changes observed for cofilin were further confirmed by quantitative Western blotting analysis with anti-actin and anti-cofilin antibodies. Indirect immunofluorescence staining with the same antibodies indicated that the microfilament network was disrupted in diazinon-treated cells. Our data suggest that microfilament organisation is disrupted by diazinon exposure, which may be related to increased cofilin expression.

  15. Toxicokinetic-toxicodynamic modeling of quantal and graded sublethal endpoints: a brief discussion of concepts

    NARCIS (Netherlands)

    Ashauer, R.; Agatz, A.; Albert, C.; Ducrot, V.; Galic, N.G.; Hendriks, J.; Jager, T.; Kretschmann, A.; O'Connor, I.; Rubach, M.N.; Nyman, M.; Schmitt, W.; Stadnicka, J.; Brink, van den P.J.

    2011-01-01

    We report on the advantages and problems of using toxicokinetic-toxicodynamic (TKTD) models for the analysis, understanding, and simulation of sublethal effects. Only a few toxicodynamic approaches for sublethal effects are available. These differ in their effect mechanism and emphasis on linkages

  16. Biological radiation effects

    International Nuclear Information System (INIS)

    Russo, A.

    2000-01-01

    Everyone is exposed to a complex mix of electromagnetic fields (EMF) of different frequencies that permeate our environment. Exposures to these EMF are increasing significantly as technology advances unabated and new applications are found. Technological progress in the broadest sense of the word has always been associated with various hazards and risks, both perceived and real. The industrial, commercial and household application on EMF is no exception. Throughout the world, the general public is concerned that exposure to EMF from such sources as high voltage power lines, broadcasting networks, mobile telephones and their base stations could lead to adverse health consequences, especially in children. As a result, the construction of new power lines and broadcasting and mobile telephone network has met with considerable opposition in many countries. Public exposure to EMF is regulated by a variety of voluntary and legal limits, together with various national safety standards. Guidelines are designed to avoid all identified hazards, from short and long term exposure, recommended limits. The aim of this paper is to report the summary of the actual scientific knowledge about the potential health effects and hazards due to man made EMF and the new tendencies of the social and political choices [it

  17. Biological effects of nuclear weapons

    International Nuclear Information System (INIS)

    Frischauf, H.

    1983-01-01

    Prompt and delayed biological effects of nuclear weapons are discussed. The response to excess pressure on man is estimated, the acute radiation syndrome caused by different radiation doses and cancerogenous and genetic effects are described. Medical care after a nuclear explosion would be difficult and imperfect. (M.J.)

  18. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Heribanova, A.

    1995-01-01

    The basic principles and pathways of effects of ionizing radiation on living organisms and cells are outlined. The following topics are covered: effects of radiation on living matter (direct effects, radical or indirect effects, dual radiation action, and molecular biological theories); effects of radiation on cells and tissues (cell depletion, changes in the cytogenetic information, reparation mechanisms), dose-response relationship (deterministic effects, stochastic effects), and the effects of radiation on man (acute radiation sickness, acute local changes, fetus injuries, non-tumorous late injuries, malignant tumors, genetic changes). (P.A.). 3 tabs., 2 figs., 5 refs

  19. Accumulation and Sublethal Effects of Triclosan and its Transformation Product Methyl-triclosan in the Earthworm Eisenia andrei Exposed to Environmental Concentrations in an Artificial Soil.

    Science.gov (United States)

    Chevillot, Fanny; Guyot, Mélanie; Desrosiers, Mélanie; Cadoret, Nicole; Veilleux, Éloïse; Cabana, Hubert; Bellenger, Jean-Philippe

    2018-04-18

    Municipal biosolids are increasingly used as a low-cost fertilizer in agricultural soil. Biosolids are contaminated by low concentrations (ng g -1 dw range) of a large variety of organic contaminants, such as triclosan (TCS). The effect of exposure to low concentrations of organic contaminants on soil biota remains largely undocumented. We evaluated the sublethal effects of TCS on the earthworm Eisenia andrei using an artificial soil amended with a nominal concentration of TCS of 50 ng g -1 dry weight soil. Using a 56-d reproduction test, we monitored the effect of TCS exposure on adult earthworm survival, growth, and reproduction. The bioaccumulation of TCS in earthworm tissue (adults and juveniles) and degradation of TCS were monitored. The genotoxicity of TCS was evaluated using a comet assay (DNA damage) on adult earthworm coelomocytes. Exposure to a low concentration of TCS had no significant effects on adult earthworm survival and DNA damage, but significantly stimulated growth (P increase in the number of cocoons and juveniles, and a decrease in the mean dry weight of juveniles. The bioaccumulation of TCS in earthworms was moderate (bioaccumulation factor ∼ 2). In biosolid-borne trials, the bioaccumulation of methyl-triclosan in earthworm tissues was higher than the parent compound TCS. We conclude that exposure to low concentrations of TCS in artificial soil can significantly affect the growth and reproductive performance of earthworms (i.e., E. andrei). More research is required with natural soils to assess TCS bioavailability for earthworms. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. Lethal and sublethal effects of pesticides on Chrysoperla carnea larvae (Neuroptera: Chrysopidae) and the influence of rainfastness in their degradation pattern over time.

    Science.gov (United States)

    Maia, Jader Braga; Carvalho, Geraldo Andrade; Medina, Pilar; Garzón, Agustín; Gontijo, Pablo da Costa; Viñuela, Elisa

    2016-07-01

    The predator Chrysoperla carnea is a model species for the study of non-target effects of pesticides under different scenarios: registration of plant protection products under the European Union and effects of the Bt toxin. Laboratory and persistence studies were carried out with six pesticides currently used in corn crops in Spain that were applied at their maximum field recommended concentrations. The assessed end-points were larval mortality, survivorship until adult stage, duration of the larval and pupal periods, fecundity, fertility and sex ratio of the emerged adults. Based on the total effect (lethal and sublethal) caused to L3 larvae in contact with fresh residues in the laboratory, pendimethalin was harmless (IOBC 1), lambda-cyhalothrin, abamectin, and hexythiazox were slightly harmful (IOBC 2), deltamethrin was moderately harmful (IOBC 3) and chlorpyrifos was harmful (IOBC 4). Afterwards, the residues of the two most toxic pesticides in the lab (deltamethrin and chlorpyrifos) were aged under greenhouse conditions (22 ± 2 °C, 40 ± 10 % R.H., 16.9 μmol m(-2) s(-1) UV radiation) in the presence and absence of artificial rainfall (10 l m(-2) h(-1), applied 24 h after pesticide application). Deltamethrin was classified as short lived (IOBC A) in both cases. However, degradation of chlorpyrifos residues was accelerated in the presence of rainfall, leading to the classification as slightly persistent (IOBC B), while in absence of rainfall it behaved as persistent (IOBC D). Every pesticide can be recommended for inclusion in corn IPM programs where the predator is present except chlorpyrifos that exhibited high direct toxicity in the lab and prolonged residual action even in the presence of rainfall.

  1. Exposure to a widespread non-pathogenic bacterium magnifies sublethal pesticide effects in the damselfly Enallagma cyathigerum: From the suborganismal level to fitness-related traits

    International Nuclear Information System (INIS)

    Janssens, Lizanne; Stoks, Robby

    2013-01-01

    While there is increasing concern that pesticide stress can interact with stress imposed by antagonistic species including pathogens, it is unknown whether this also holds for non-pathogenic bacteria. We exposed Enallagma cyathigerum damselfly larvae to the pesticide chlorpyrifos and a non-pathogenic Escherichia coli strain. Both exposure to chlorpyrifos and E. coli reduced growth rate and fat storage, probably due to the observed energetically costly increases in physiological defence (glutathione-S-transferase and Hsp70) and, for E. coli, immune defence (phenoloxidase). Moreover, these stressors interacted for both fitness-related traits. Most importantly, another fitness-related trait, bacterial load, increased drastically with chlorpyrifos concentration. A possible explanation is that the upregulation of phenoloxidase in the presence of E. coli changed into a downregulation when combined with chlorpyrifos. We argue that the observed interactive, partly synergistic effects between pesticides and widespread non-pathogenic bacteria may be common and deserves further attention to improve ecological risk assessment of pesticides. -- Highlights: ► Non-pathogens such as the bacterium E. coli are ignored in ecotoxicology. ► Both E. coli and chlorpyrifos impaired fitness-related traits in damselfly larvae. ► E. coli modulated and magnified effects of chlorpyrifos on physiology and fitness. ► Bacterial load was magnified >10× in the presence of chlorpyrifos. ► Risk assessment of pesticides should consider synergisms with non-pathogens. -- Non-pathogenic bacteria reduce fitness-related traits and can synergistically interact with sublethal pesticide effects for physiological and fitness-related traits

  2. Sub-lethal effects of the neurotoxic pyrethroid insecticide Fastac 50EC on the general motor and locomotor activities of the non-targeted beneficial carabid beetle Platynus assimilis (Coleoptera: Carabidae).

    Science.gov (United States)

    Tooming, Ene; Merivee, Enno; Must, Anne; Sibul, Ivar; Williams, Ingrid

    2014-06-01

    Sub-lethal effects of pesticides on behavioural endpoints are poorly studied in carabids (Coleoptera: Carabidae) though changes in behaviour caused by chemical stress may affect populations of these non-targeted beneficial insects. General motor activity and locomotion are inherent in many behavioural patterns, and changes in these activities that result from xenobiotic influence mirror an integrated response of the insect to pesticides. Influence of pyrethroid insecticides over a wide range of sub-lethal doses on the motor activities of carabids still remains unclear. Video tracking of Platynus assimilis showed that brief exposure to alpha-cypermethrin at sub-lethal concentrations ranged from 0.01 to 100 mg L(-1) caused initial short-term (24 h) locomotor hypo-activity. In addition, significant short- and long-term concentration and time-dependent changes occurred in general motor activity patterns and rates. Conspicuous changes in motor activity of Platynus assimilis beetles treated at alpha-cypermethrin concentrations up to 75,000-fold lower than maximum field recommended concentration (MFRC) suggest that many, basic fitness-related behaviours might be severely injured as well. These changes may negatively affect carabid populations in agro-ecosystems. Long-term hypo-activity could directly contribute to decreased trap captures of carabids frequently observed after insecticide application in the field. © 2013 Society of Chemical Industry.

  3. Evaluating the stress response as a bioindicator of sub-lethal effects of crude oil exposure in wild house sparrows (Passer domesticus.

    Directory of Open Access Journals (Sweden)

    Christine R Lattin

    Full Text Available Petroleum can disrupt endocrine function in humans and wildlife, and interacts in particularly complex ways with the hypothalamus-pituitary-adrenal (HPA axis, responsible for the release of the stress hormones corticosterone and cortisol (hereafter CORT. Ingested petroleum can act in an additive fashion with other stressors to cause increased mortality, but it is not clear exactly why--does petroleum disrupt feedback mechanisms, stress hormone production, or both? This laboratory study aimed to quantify the effects of ingested Gulf of Mexico crude oil on the physiological stress response of house sparrows (Passer domesticus. We examined baseline and stress-induced CORT, negative feedback, and adrenal sensitivity in house sparrows given a 1% oil or control diet (n = 12 in each group. We found that four weeks on a 1% oil diet did not alter baseline CORT titers or efficacy of negative feedback, but significantly reduced sparrows' ability to secrete CORT in response to a standardized stressor and adrenocorticotropin hormone injection, suggesting that oil damages the steroid-synthesizing cells of the adrenal. In another group of animals on the same 1% oil (n = 9 or control diets (n = 8, we examined concentrations of eight different blood chemistry parameters, and CORT in feathers grown before and during the feeding experiments as other potential biomarkers of oil exposure. None of the blood chemistry parameters differed between birds on the oil and control diets after two or four weeks of feeding, nor did feather CORT differ between the two groups. Overall, this study suggests that the response of CORT to stressors, but not baseline HPA function, may be a particularly sensitive bioindicator of sub-lethal chronic effects of crude oil exposure.

  4. Evaluating the stress response as a bioindicator of sub-lethal effects of crude oil exposure in wild house sparrows (Passer domesticus).

    Science.gov (United States)

    Lattin, Christine R; Ngai, Heather M; Romero, L Michael

    2014-01-01

    Petroleum can disrupt endocrine function in humans and wildlife, and interacts in particularly complex ways with the hypothalamus-pituitary-adrenal (HPA) axis, responsible for the release of the stress hormones corticosterone and cortisol (hereafter CORT). Ingested petroleum can act in an additive fashion with other stressors to cause increased mortality, but it is not clear exactly why--does petroleum disrupt feedback mechanisms, stress hormone production, or both? This laboratory study aimed to quantify the effects of ingested Gulf of Mexico crude oil on the physiological stress response of house sparrows (Passer domesticus). We examined baseline and stress-induced CORT, negative feedback, and adrenal sensitivity in house sparrows given a 1% oil or control diet (n = 12 in each group). We found that four weeks on a 1% oil diet did not alter baseline CORT titers or efficacy of negative feedback, but significantly reduced sparrows' ability to secrete CORT in response to a standardized stressor and adrenocorticotropin hormone injection, suggesting that oil damages the steroid-synthesizing cells of the adrenal. In another group of animals on the same 1% oil (n = 9) or control diets (n = 8), we examined concentrations of eight different blood chemistry parameters, and CORT in feathers grown before and during the feeding experiments as other potential biomarkers of oil exposure. None of the blood chemistry parameters differed between birds on the oil and control diets after two or four weeks of feeding, nor did feather CORT differ between the two groups. Overall, this study suggests that the response of CORT to stressors, but not baseline HPA function, may be a particularly sensitive bioindicator of sub-lethal chronic effects of crude oil exposure.

  5. Biological effects of electromagnetic fields

    International Nuclear Information System (INIS)

    David, E.

    1993-01-01

    In this generally intelligible article, the author describes at first the physical fundamentals of electromagnetic fields and their basic biological significance and effects for animals and human beings before dealing with the discussion regarding limiting values and dangers. The article treats possible connections with leukaemia as well as ith melatonine production more detailed. (vhe) [de

  6. Impacts of chronic sublethal exposure to clothianidin on winter honeybees.

    Science.gov (United States)

    Alkassab, Abdulrahim T; Kirchner, Wolfgang H

    2016-07-01

    A wide application of systemic pesticides and detection of their residues in bee-collected pollen and nectar at sublethal concentrations led to the emergence of concerns about bees' chronic exposure and possible sublethal effects on insect pollinators. Therefore, special attention was given to reducing unintentional intoxications under field conditions. The sensitivity of winter bees throughout their long lifespan to residual exposure of pesticides is not well known, since most previous studies only looked at the effects on summer bees. Here, we performed various laboratory bioassays to assess the effects of clothianidin on the survival and behavior of winter bees. Oral lethal and sublethal doses were administered throughout 12-day. The obtained LD50 values at 48, 72, 96 h and 10 days were 26.9, 18.0, 15.1 and 9.5 ng/bee, respectively. Concentrations <20 µg/kg were found to be sublethal. Oral exposure to sublethal doses was carried out for 12-day and, the behavioral functions were tested on the respective 13th day. Although slight reductions in the responses at the concentrations 10 and 15 µg/kg were observed, all tested sublethal concentrations had showed non-significant effects on the sucrose responsiveness, habitation of the proboscis extension reflex and olfactory learning performance. Nevertheless, chronic exposure to 15 µg/kg affected the specificity of the early long-term memory (24 h). Since the tested concentrations were in the range of field-relevant concentrations, our results strongly suggest that related-effects on winter and summer bees' sensitivity should also be studied under realistic conditions.

  7. Biological effectiveness of antiproton annihilation

    DEFF Research Database (Denmark)

    Holzscheiter, M.H.; Agazaryan, N.; Bassler, Niels

    2004-01-01

    We describe an experiment designed to determine whether or not the densely ionizing particles emanating from the annihilation of antiprotons produce an increase in ‘‘biological dose’’ in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct...... measurement of the biological effects of antiproton annihilation. The experiment has been approved by the CERN Research Board for running at the CERN Antiproton Decelerator (AD) as AD-4/ACE (Antiproton Cell Experiment) and has begun data taking in June of 2003. The background, description and the current...

  8. Biological effectiveness of antiproton annihilation

    CERN Document Server

    Holzscheiter, Michael H.; Bassler, Niels; Beyer, Gerd; De Marco, John J.; Doser, Michael; Ichioka, Toshiyasu; Iwamoto, Keisuke S.; Knudsen, Helge V.; Landua, Rolf; Maggiore, Carl; McBride, William H.; Møller, Søren Pape; Petersen, Jorgen; Smathers, James B.; Skarsgard, Lloyd D.; Solberg, Timothy D.; Uggerhøj, Ulrik I.; Withers, H.Rodney; Vranjes, Sanja; Wong, Michelle; Wouters, Bradly G.

    2004-01-01

    We describe an experiment designed to determine whether or not the densely ionizing particles emanating from the annihilation of antiprotons produce an increase in “biological dose” in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct measurement of the biological effects of antiproton annihilation. The experiment has been approved by the CERN Research Board for running at the CERN Antiproton Decelerator (AD) as AD-4/ACE (Antiproton Cell Experiment) and has begun data taking in June of 2003. The background, description and the current status of the experiment are given.

  9. Synergistic Effect of Bone Marrow Transplantation and Bradykinin Potential Factor Isolated from Venom on Thymus and Spleen of Sublethally Irradiated Guinea Pigs

    International Nuclear Information System (INIS)

    Abu-Sinna, G.; Kafafy, Y.; Nassar, A.Y.; Salman, A.

    2005-01-01

    The buthus occitanus, scorpion venom contains a strong bradykinin potentiating factor (BPF) that augments bradykinin effects through enhancing its release. Based on the cytoprotective ability of BPF, the present work investigates it as a radioprotectant. Sublethal whole-body y-irradiation at 1.5 Gy was used. Bone marrow cells suspension (BM cells) alone or in combination with BPF was utilized. Three to four weeks-aged male Guinea pigs were grouped into two major groups. The first was non-irradiated control that was divided into subgroups treated i.p. with BM cells (2.5xl06 cells), one dose of BPF (lug/g b wt), BM cells+ BPF, one week spaced two doses of BPF, BM cells+ 2 doses of BPF, one week spaced three doses of BPF or BM cells+ 3 doses of BPF. Second major group (irradiated group) at 1.5 Gy that, subdivided and treated similarly. 5 animals from each group were killed at 7, 14 and 21 days from the initiation of treatment (3 h after irradiation). The subgroups of non-irradiated animals showed an increase in spleen wt and colony formation, thymus population, and globulins content particularly in those subgroups that stayed for the later time periods (14 and 21 days) and that treated with combined BM cells+ BPF or that groups that were treated with two or three BPF doses. Irradiation caused dramatic destruction in thymus and the spleen reflected on reduction of the lower globulins content. Treatment with BM cells, BM cells+ double doses of BPF or triple doses of BPF caused complete recovery in all measured indices, the best result was observed in those of subgroups treated with BM cells+ double doses of BPF or treated with triple doses of BPF. They completely normalized the investigated parameters after 14 and 21 days respectively

  10. Survival rate of honeybee (Apis mellifera) workers after exposure to sublethal concentrations of imidacloprid

    NARCIS (Netherlands)

    Blacquiere, T.

    2010-01-01

    Imidacloprid is a commonly used systemic insecticide which can induce several sublethal effects. Previous research has not shown any increased mortality in bees that were fed with sublethal doses. However, there is very little research conducted with the focus on survival rate of honeybees in the

  11. Study effects sublethal concentration of diazinon on testis, brain and heart of Rutilus frisii kutum (Kamensky, 1901 male brood stocks

    Directory of Open Access Journals (Sweden)

    M Mohammad Nejad Shamoushaki

    2011-11-01

    Full Text Available In this study the effects of toxic pesticides, Diazinon (60% emulsion on the some tissues of (Rutilus frisii kutum, Kamensky, 1901 male brood stocks were studied. The test were studied under static water quality conditions at 15 °C ± 2 ºC in winter and spring 2009. The effective physical and chemical parameters of water were pH= 7-8.2, dh= 300 mg/L (caco3, DO= 7 ppm and T= 15 °C±2 ºC. LC50 96h pesticide Diazinon on the first 0.4 mg/L was determined and then fish were exposed by the toxin with 3 concentrations, MAC value, LC1, LC5, and a control with three replicates for 45 days. Pathology results showed toxin diazinon no effect on average weight and fish body length, the average weight of heart and brain but caueses decrease of gonad weigth and gonad index and also, cause complications of atrophy, fibrosis and necrosis in testis , vascular congestion, increased distance between the myocardium and fibrous string in heart and neuronal loss, vascular congestion and edema in the brain of kutum male brood stocks.

  12. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Marko, A.M.

    1981-05-01

    In this review radiation produced by the nuclear industry is placed into context with other sources of radiation in our world. Human health effects of radiation, derivation of standards and risk estimates are reviewed in this document. The implications of exposing the worker and the general population to radiation generated by nuclear power are assessed. Effects of radiation are also reviewed. Finally, gaps in our knowledge concerning radiation are identified and current research on biological effects, on environmental aspects, and on dosimetry of radiation within AECL and Canada is documented in this report. (author)

  13. Effects of sub-lethal levels of dichlorodiphenyltrichloroethane and dichlorodiphenyldichloroethylene on in vitro steroid biosynthesis by ovarian follicles or steroid metabolism by embryos of rainbow trout (Oncorhynchus mykiss)

    International Nuclear Information System (INIS)

    Petkam, Rakpong; Renaud, Rick; Lin, Lucy; Boermans, Herman; Leatherland, John

    2005-01-01

    This study examined the possibility that DDT and DDE, at sub-lethal exposure levels, exert direct effects on the biotransformation of gonadal steroids by rainbow trout (Oncorhynchus mykiss) ovarian follicles and embryos. Ovarian follicles were co-incubated with DDT or DDE at 0.01 or 1 mg l -1 to examine effects of the pesticides on basal or cAMP-activated steroidogenesis. Ovarian preparations were incubated with radiolabelled [ 3 H]pregnenolone ([ 3 H]P 5 ), and the tritiated metabolites of [ 3 H]P 5 metabolism were separated using high-performance liquid chromatography (HPLC). Testosterone (T) and 17β-estradiol (E 2 ) production were also measured using radioimmunoassay (RIA). Embryos were either exposed to the pesticides in ovo, or co-incubated in vitro with the pesticides. The effect of the pesticides on embryo steroid biotransformation was examined using a range of radioactively labelled substrates, including [ 3 H]P 5 , [ 3 H]progesterone ([ 3 H]P 4 ), [ 3 H]T and [ 3 H]E 2 . At the concentrations used, the pesticides had no significant effect on the relative amounts of unconjugated radiolabelled steroids formed by the biotransformation of [ 3 H]P 5 under conditions of basal or cAMP-stimulated ovarian steroidogenesis. However, DDT and DDE appeared to reduce the basal accumulation of androgen as a product of P 5 biotransformation by ovarian follicles. Basal or cAMP-stimulated total estrogen production was not affected. In addition, DDT at 1 mg l -1 and DDE at 0.01 mg l -1 significantly increased and decreased cAMP-stimulated T accumulation, respectively. Also DDT at 0.01 mg l -1 and DDE at 1 mg l -1 significantly increased and decreased basal E 2 accumulation, respectively. The steroid metabolites synthesized from the different substrates by embryos were essentially similar in both controls and pesticide-exposed groups, and the survival of embryos to hatch was not significantly affected by pesticide exposure, in ovo, with an approximately 90% hatchability in

  14. Effects of sub-lethal levels of dichlorodiphenyltrichloroethane and dichlorodiphenyldichloroethylene on in vitro steroid biosynthesis by ovarian follicles or steroid metabolism by embryos of rainbow trout (Oncorhynchus mykiss)

    Energy Technology Data Exchange (ETDEWEB)

    Petkam, Rakpong [Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ont., N1G 2W1 (Canada); Renaud, Rick [Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ont., N1G 2W1 (Canada); Lin, Lucy [Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ont., N1G 2W1 (Canada); Boermans, Herman [Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ont., N1G 2W1 (Canada); Leatherland, John [Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ont., N1G 2W1 (Canada)]. E-mail: jleather@ovc.uoguelph.ca

    2005-07-01

    This study examined the possibility that DDT and DDE, at sub-lethal exposure levels, exert direct effects on the biotransformation of gonadal steroids by rainbow trout (Oncorhynchus mykiss) ovarian follicles and embryos. Ovarian follicles were co-incubated with DDT or DDE at 0.01 or 1 mg l{sup -1} to examine effects of the pesticides on basal or cAMP-activated steroidogenesis. Ovarian preparations were incubated with radiolabelled [{sup 3}H]pregnenolone ([{sup 3}H]P{sub 5}), and the tritiated metabolites of [{sup 3}H]P{sub 5} metabolism were separated using high-performance liquid chromatography (HPLC). Testosterone (T) and 17{beta}-estradiol (E{sub 2}) production were also measured using radioimmunoassay (RIA). Embryos were either exposed to the pesticides in ovo, or co-incubated in vitro with the pesticides. The effect of the pesticides on embryo steroid biotransformation was examined using a range of radioactively labelled substrates, including [{sup 3}H]P{sub 5}, [{sup 3}H]progesterone ([{sup 3}H]P{sub 4}), [{sup 3}H]T and [{sup 3}H]E{sub 2}. At the concentrations used, the pesticides had no significant effect on the relative amounts of unconjugated radiolabelled steroids formed by the biotransformation of [{sup 3}H]P{sub 5} under conditions of basal or cAMP-stimulated ovarian steroidogenesis. However, DDT and DDE appeared to reduce the basal accumulation of androgen as a product of P{sub 5} biotransformation by ovarian follicles. Basal or cAMP-stimulated total estrogen production was not affected. In addition, DDT at 1 mg l{sup -1} and DDE at 0.01 mg l{sup -1} significantly increased and decreased cAMP-stimulated T accumulation, respectively. Also DDT at 0.01 mg l{sup -1} and DDE at 1 mg l{sup -1} significantly increased and decreased basal E{sub 2} accumulation, respectively. The steroid metabolites synthesized from the different substrates by embryos were essentially similar in both controls and pesticide-exposed groups, and the survival of embryos to hatch

  15. Sublethal effects of copper nanoparticles on the histology of gill, liver and kidney of the Caspian roach, Rutilus rutilus caspicus

    Directory of Open Access Journals (Sweden)

    Sh. Aghamirkarimi

    2017-09-01

    Full Text Available The current study has determined the toxicity effects of copper nanoparticles on the some vital organs such as gill, liver and kidney of Caspian Roach; Rutillus rutillus caspicus. For this purpose, 120 fishes were used as experimental samples and exposed to 0.1, 0.2 and 0.5 mg/L of Cu nanoparticles for 21 days, and 30 fishes assumed as the experiment control. The mean water temperature of the aquaria was 22±2 ºC, dissolved oxygen 5.2 mg/L, pH at 7±0.004 and the concentration of calcium carbonate was 270 ppm. On 7, 14 and 21 days after exposing the fishes to copper nanoparticles, three fishes were randomly selected from each aquaria, sacrificed and samples from their gill, liver and kidney were taken and fixed in cold 10 % buffered formalin. Then microscopic sections were prepared and examined by light microscope which showed histological alternations in the gill, liver and kidney tissues. Evaluation of these changes could be useful in estimating the harmful effects of copper nanoparticles. Histological alternation in gills included: hyperplasia, fusion and detachment of secondary lamellae, blood congestion in vascular axis of primary filaments, reduced secondary lamellae length and cellular degeneration. Histological changes in liver included blood congestion in the central veins, cytoplasmic vacuolation of the hepatocytes, cellular degeneration and congestion in the blood sinusoids and necrosis of the hepatocytes. Histological changes in kidneys included glomerular shrinkage, severe degeneration in the tubules cells, interstitial tissue and glomerulus, increase in interstitial tissue cells and macrophages aggregation. The degree of damages was more intensive at higher copper nanoparticles concentrations. The result of the study showed that copper nanoparticles could cause severe damages in the vital tissues of Caspian roach; Rutillus rutillus caspicus and have lethal effects for fish.

  16. Cadmium accumulation, gill Cd binding, acclimation, and physiological effects during long term sublethal Cd exposure in rainbow trout

    International Nuclear Information System (INIS)

    Hollis, L.; McGeer, J.C.; McDonald, D.G.; Wood, C.M.

    1999-01-01

    Juvenile rainbow trout, on 3% of body weight daily ration, were exposed to 0 (control), 3, and 10 μg l -1 Cd (as Cd(NO 3 ) 2 · 4H 2 O) in moderately hard (140 mg l -1 as CaCO 3 ), alkaline (95 mg l -1 as CaCO 3 , pH 8.0) water for 30 days. Particular attention focused on acclimation, and on whether a gill surface binding model, originally developed in dilute softwater, could be applied in this water quality to fish chronically exposed to Cd. Only the higher Cd concentration caused mortality (30%, in the first few days). The costs of acclimation, if any, in our study were subtle since no significant effects of chronic Cd exposure were seen in growth rate, swimming performance (stamina and U Crit ), routine O 2 consumption, or whole body ion levels. Substantial acclimation occurred in both exposure groups, manifested as 11- to 13-fold increases in 96-h LC 50 values. In water quality regulations, which are based on toxicity tests with non-acclimated fish only, this remarkable protective effect of acclimation is not taken into account. Cd accumulated in a time- and concentration-dependent fashion to 60-120x (gills), 8-20x (liver), 2-7x (carcass), and 5-12x (whole bodies) control levels by 30 days. Chronically accumulated gill Cd could not be removed by ethylenediaminetetraacetic acid (EDTA) challenge. These gill Cd concentrations were 20- to 40-fold greater than levels predicted by the gill-binding model to cause mortality during acute exposure. In short-term gill Cd-binding experiments (up to 70 μg l -1 exposures for 3 h), gill Cd burden increased as predicted in control fish, but was not detectable against the high background concentrations in acclimated fish. In light of these results, Cd uptake/turnover tests were performed using radioactive 109 Cd to improve sensitivity. With this approach, a small saturable binding component was seen, but could not be related to toxic response in acclimated fish. Acclimated trout internalized less 109 Cd than control fish, but

  17. Cadmium accumulation, gill Cd binding, acclimation, and physiological effects during long term sublethal Cd exposure in rainbow trout

    Energy Technology Data Exchange (ETDEWEB)

    Hollis, L.; McGeer, J.C.; McDonald, D.G.; Wood, C.M. [Department of Biology, McMaster University, Hamilton, Ontario (Canada)

    1999-07-01

    Juvenile rainbow trout, on 3% of body weight daily ration, were exposed to 0 (control), 3, and 10 {mu}g l{sup -1} Cd (as Cd(NO{sub 3}){sub 2} {center_dot} 4H{sub 2}O) in moderately hard (140 mg l{sup -1} as CaCO{sub 3}), alkaline (95 mg l{sup -1} as CaCO{sub 3}, pH 8.0) water for 30 days. Particular attention focused on acclimation, and on whether a gill surface binding model, originally developed in dilute softwater, could be applied in this water quality to fish chronically exposed to Cd. Only the higher Cd concentration caused mortality (30%, in the first few days). The costs of acclimation, if any, in our study were subtle since no significant effects of chronic Cd exposure were seen in growth rate, swimming performance (stamina and U{sub Crit}), routine O{sub 2} consumption, or whole body ion levels. Substantial acclimation occurred in both exposure groups, manifested as 11- to 13-fold increases in 96-h LC{sub 50} values. In water quality regulations, which are based on toxicity tests with non-acclimated fish only, this remarkable protective effect of acclimation is not taken into account. Cd accumulated in a time- and concentration-dependent fashion to 60-120x (gills), 8-20x (liver), 2-7x (carcass), and 5-12x (whole bodies) control levels by 30 days. Chronically accumulated gill Cd could not be removed by ethylenediaminetetraacetic acid (EDTA) challenge. These gill Cd concentrations were 20- to 40-fold greater than levels predicted by the gill-binding model to cause mortality during acute exposure. In short-term gill Cd-binding experiments (up to 70 {mu}g l{sup -1} exposures for 3 h), gill Cd burden increased as predicted in control fish, but was not detectable against the high background concentrations in acclimated fish. In light of these results, Cd uptake/turnover tests were performed using radioactive {sup 109}Cd to improve sensitivity. With this approach, a small saturable binding component was seen, but could not be related to toxic response in

  18. Sublethal effects of Cry 1F Bt corn and clothianidin on black cutworm (Lepidoptera: Noctuidae) larval development.

    Science.gov (United States)

    Kullik, Sigrun A; Sears, Mark K; Schaafsma, Arthur W

    2011-04-01

    Black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), is an occasional pest of maize (corn), Zea mays L., that may cause severe stand losses and injury to corn seedlings. The efficacy of the neonicotinoid seed treatment clothianidin at two commercially available rates and their interaction with a transgenic corn hybrid (Bt corn), trait expressing the Bacillus thuringiensis variety aizawai insecticidal toxin Cry 1Fa2, against black cutworm larvae was investigated. Clothianidin at a rate of 25 mg kernel(-1) on Bt corn increased larval mortality and reduced larval weight gains additively. In contrast, weights of larvae fed non-Bt corn seedlings treated with clothianidin at a rate of 25 mg kernel(-1) increased significantly, suggesting either compensatory overconsumption, hormesis, or hormoligosis. Both Bt corn alone and clothianidin at a rate of 125 mg kernel(-1) applied to non-Bt corn seedlings caused increased mortality and reduced larval weight gains. In two field trials, plots planted with Bt corn hybrids consistently had the highest plant populations and yields, regardless of whether they were treated with clothianidin at the lower commercial rate of 25 mg kernel(-1) The use of Bt corn alone or in combination with the low rate of clothianidin (25 mg kernel(-1)) seems suitable as a means of suppressing black cutworm in no-tillage cornfields, although rescue treatments may still be necessary under severe infestations. Clothianidin alone at the low rate of 25 mg kernel(-1) is not recommended for black cutworm control until further studies of its effects on larval physiology and field performance have been completed.

  19. The biological effects of radiation

    International Nuclear Information System (INIS)

    Sykes, D.A.

    1979-01-01

    The hazards of radiations to man are briefly covered in this paper. The natural background sources of radiations are stated and their resulting doses are compared to those received voluntarily by man. The basis of how radiations cause biological damage is given and the resulting somatic effects are shown for varying magnitude of dose. Risk estimates are given for cancer induction and genetic effects are briefly discussed. Finally four case studies of radiation damage to humans are examined exemplifying the symptoms of large doses of radiations [af

  20. Effects of Thy-1+ cell depletion on the capacity of donor lymphoid cells to induce tolerance across an entire MHC disparity in sublethally irradiated adult hosts

    International Nuclear Information System (INIS)

    Pierce, G.E.; Watts, L.M.

    1989-01-01

    Thy-1+ cell depletion with anti-Thy-1.2 mAb and complement markedly reduced the capacity of C57BL/6J, H-2b bone marrow to establish mixed lymphoid chimerism and induce tolerance to C57BL/6J skin grafts across an entire MHC disparity in BALB/c, H-2d hosts conditioned with sublethal, fractionated 7.5 Gy total-body irradiation. In this model tolerance can be transferred to secondary irradiated BALB/c hosts only by cells of C57BL/6J donor, not host, genotype isolated from the spleens of tolerant hosts. Thy-1+ cell depletion abolished the capacity of C57BL/6J donor cells from tolerant BALB/c host spleens to transfer tolerance. The capacity of semiallogeneic BALB/c x C57BL/6J F1, H-2d/b donor BM and spleen cells to induce chimerism and tolerance to C57BL/6J skin grafts in BALB/c parental hosts was also reduced by Thy-1+ cell depletion. Thus the requirement for donor Thy-1+ cells cannot be explained simply on the basis of alloaggression. It is unlikely that the requisite Thy-1+ cells are nonspecific suppressor cells: Thy-1+ cell depletion had no effect on the slight but significant prolongation of third-party C3H/HeJ, H-2k skin grafts in irradiated BALB/c hosts injected with allogeneic C57BL/6J or semiallogeneic BALB/c x C57BL/6J F1 BM compared to irradiated controls injected with medium only. Furthermore, injections of semiallogeneic F1 spleen cells had no significant effect on the survival of the third-party grafts, although these cells were fully capable of inducing tolerance, and their capacity to induce tolerance was significantly reduced by Thy-1+ cell depletion. The requirement for a specific population of lymphoid cells, i.e. Thy-1+, remains unexplained but suggests that donor cells might play a role in the induction or maintenance of tolerance in this model other than merely providing a circulating source of donor antigens

  1. Uptake, metabolism and sub-lethal effects of BDE-47 in two estuarine invertebrates with different trophic positions

    International Nuclear Information System (INIS)

    Díaz-Jaramillo, M.; Miglioranza, K.S.B.; Gonzalez, M.; Barón, E.; Monserrat, J.M.; Eljarrat, E.; Barceló, D.

    2016-01-01

    Two microcosm types -sediment-biota and biota-biota- were constructed to simulate different pathways of BDE-47 uptake, metabolism and oxidative stress effects in two key estuarine invertebrates (polychaete Laeonereis acuta and crab Cyrtograpsus angulatus). In the sediment-biota experiment, both species were exposed to spiked sediments; an environmentally reported and a high concentration of BDE-47 for 2 weeks. In the biota-biota experiment, crabs were fed with polychaetes pre-exposed to BDE-47 in the sediment-biota experiment. The sediment-biota experiment first revealed that polychaetes significantly accumulated BDE-47 (biota-sediment accumulation factor >2; p < 0.05) to a much greater extent than the crab organs (muscle, hepatopancreas, gills) at both sediment concentrations. For oxidative stress responses, polychaete and crab tissues exposed to spiked sediment showed a significant increase (p < 0.05) of only glutathione S-transferase (GST) activity with respect to controls in both BDE-47 concentrations. No lipid peroxidation (TBARS) or total antioxidant capacity (ACAP) changes were evident in the species or organs exposed to either BDE-47 sediment concentration. The biota-biota experiment showed that feeding crabs with pre-exposed polychaetes caused BDE-47 accumulation in organs as well as significant amounts of BDE-47 eliminated through feces (p < 0.05). Unlike the sediment-biota exposure, crabs fed with pre-exposed BDE-47 polychaetes showed the most conspicuous oxidative stress responses. Significant changes in GST and ACAP in both hepatopancreas and gills, in addition to enhanced TBARS levels in the hepatopancreas with respect to controls (p < 0.05), revealed that BDE-47 assimilated by invertebrates represents a potential source of toxicity to their predators. No methoxylated metabolites (MeO-PBDEs) were detected during BDE-47 metabolism in the invertebrates in either of the two different exposure types. In contrast, hydroxylated metabolites (OH

  2. Eficiência e efeitos subletais de nim sobre Bonagota salubricola (Meyrick (Lepidoptera: Tortricidae Efficiency and sublethal effects of neem on Bonagota salubricola (Meyrick (Lepidoptera: Tortricidae

    Directory of Open Access Journals (Sweden)

    Daniel Bernardi

    2011-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a eficiência e os efeitos subletais de um inseticida à base de nim (10 g.L-1 de azadiractina A sobre a lagarta-enroladeira Bonagota salubricola em laboratório. Nos bioensaios, foi utilizado o produto à base de azadiractina NeemAzal-T/S® nas concentrações de 0,06%; 0,09%; 0,12%; 0,16%; 0,18% e 0,20% do produto comercial (p.c e uma testemunha (água destilada. A dieta artificial foi cortada em cubos e imersa nas caldas das respectivas concentrações do produto, e, em seguida, lagartas recém-eclodidas foram transferidas para tubos de vidro, contendo os cubos de dieta tratados. Quando a dieta artificial foi tratada com concentração de 0,20% do produto comercial, houve 100% da mortalidade aos 6 dias após a inoculação. Por outro lado, as concentrações de 0,16 e 0,18% prolongaram a fase larval, reduziram a viabilidade de pupas e afetaram negativamente a fecundidade do inseto.The objective of this study was to evaluate the efficiency of control and sublethal effects of neem insecticide (10 g.L-1 of azadirachtin A to the leafroller Bonagota salubricola at laboratory condition. In the bioassays, it was used an azadirachtin based product (NeemAzal-T/S® at concentrations of 0.06%, 0.09%, 0.12%, 0.16%, 0.18% and 0.20% of the commercial product (c.p. and a control (distilled water. The artificial diet was cut in cubes and immersed in the syrups of the respective product concentrations, soon afterwards recently-emerged caterpillars were transferred to glass tubes, containing the diet cubes treated. When the artificial diet was treated with a concentration of 0.20% of the commercial product, the mortality was 100% at the 6th day after inoculation. Additionally, concentrations of 0.16% and 0.18% extended the larval stages, reduced pupae viability and negatively affected the fecundity of the insect.

  3. Biological effects of electromagnetic fields

    International Nuclear Information System (INIS)

    Gabriel, C.

    1996-01-01

    The effects of electromagnetic (em) fields on biological systems were first observed and exploited well over a century ago. Concern over the possible health hazards of human exposure to such fields developed much later. It is now well known that excessive exposure to em fields may have in undesirable biological consequences. Standards were introduced to determine what constitute an excessive exposure and how to avoid it. Current concern over the issue of hazards stems mainly from recent epidemiological studies of exposed populations and also from the results of laboratory experiments in which whole animals are exposed in vivo or tissue and cell cultures exposed in vitro to low levels of irradiation. The underlying fear is the possibility of a causal relationship between chronic exposure to low field levels and some forms of cancer. So far the evidence does not add up to a firm statement on the matter. At present it is not known how and at what level, if at all, can these exposure be harmful to human health. This state of affair does not provide a basis for incorporating the outcome of such research in exposure standards. This paper will give a brief overview of the research in this field and how it is evaluated for the purpose of producing scientifically based standards. The emphasis will be on the physical, biophysical and biological mechanisms implicated in the interaction between em fields and biological systems. Understanding such mechanisms leads not only to a more accurate evaluation of their health implications but also to their optimal utilization, under controlled conditions, in biomedical applications. (author)

  4. Biological effects of heavy particles

    International Nuclear Information System (INIS)

    Sabatier, L.; Martins, B.; Dutrillaux, B.

    1991-01-01

    The usual definitions of biological dose and biological dosimetry do not fit in case of particles with high linear energy transfer (LET). The dose corresponds to an average value which is not representative of the highly localized energy transfer due to heavy ions. Fortunately, up to now, a biological dosimetry following an exposure to high LET particles is necessary only for cosmonauts. In radiotherapy applications, one exactly knows the nature and energy of incident particle beams. The quality requirements for a good biodosimeter include reliable relation between dose and effect, weak sensitivity to individual variations, reliability and stability of acquired informations against the time delay between exposure and measurements. Nothing is better than the human lymphocyte to be used for measurements that fulfil these requirements. In the case of a manned spaceship, the irradiation dose corresponds to a wide range of radiation (protons, neutrons, heavy ions), and making a dosimetry as well as defining it are of current concern. As yet, there exist two possible definitions, which reduce the dose either to a proton or to a neutron equivalent one. However, such an approximation is not a faithful representation of the irradiation effects and in particular, the long-term effects may be quite different. In the future, it is reasonable to expect an evolution towards technics that enable identifying irradiated cells and quantifying precisely their radiation damage in order to reconstruct the spectrum of particles received by a given cosmonaut in a given time. Let us emphasize that the radiation hazards due to a short stay in space are quite minor, but in the case of a travel to Mars, they cannot be neglected [fr

  5. Making sense of nickel accumulation and sub-lethal toxic effects in saline waters: Fate and effects of nickel in the green crab, Carcinus maenas.

    Science.gov (United States)

    Blewett, Tamzin A; Glover, Chris N; Fehsenfeld, Sandra; Lawrence, Michael J; Niyogi, Som; Goss, Greg G; Wood, Chris M

    2015-07-01

    In freshwater, invertebrates nickel (Ni) is considered an ionoregulatory toxicant, but its mechanism of toxicity in marine settings, and how this varies with salinity, is poorly understood. This study investigated Ni accumulation and physiological mechanisms of sub-lethal Ni toxicity in the euryhaline green crab Carcinus maenas. Male crabs were exposed to 8.2μg/L (the US EPA chronic criterion concentration for salt waters) of waterborne Ni (radiolabelled with (63)Ni) at three different salinities, 20%, 60% and 100% SW for 24h. Whole body Ni accumulation in 20% SW was 3-5 fold greater than in 60% or 100% SW, and >80% of accumulated Ni was in the carapace at all salinities. Ni also accumulated in posterior gill 8, which showed a higher accumulation in 20% SW than in other salinities, a pattern also seen at higher exposure concentrations of Ni (500 and 3000μg/L). Gill perfusion experiments revealed that Ni was taken up by both anterior and posterior gills, but in 20% SW the posterior gill 8, which performs ionoregulatory functions, accumulated more Ni than the anterior gill 5, which primarily has a respiratory function. The sub-lethal consequences of Ni exposure were investigated by placing crabs in Ni concentrations of 8.2, 500, and 3000μg/L at 20, 60 or 100% SW for 24h. In 20% SW, haemolymph Ca levels were significantly decreased by exposure to Ni concentrations of 8.2μg/L or higher, whereas Na concentrations were depressed only at 3000μg/L. Na(+)/K(+)-ATPase activity was inhibited at both 500 and 3000μg/L in gill 8, but only in 20% SW. Haemolymph K, Mg, and osmolality were unaffected throughout, though all varied with salinity in the expected fashion. These data suggest that Ni impacts ionoregulatory function in the green crab, in a gill- and salinity-dependent manner. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Physical basis for biological effect

    International Nuclear Information System (INIS)

    Goodhead, D.T.

    1987-01-01

    Absorbed dose, or particle fluence, alone, are poor predictors of the biological effectiveness of ionizing radiations. Various radiation 'quality' parameters have been proposed to account quantitatively for the differences due to type of radiation. These include LET, quality factor (Q), lineal energy, specific energy and Z 2 /β 2 . However, all of these have major shortcomings, largely because they fail to describe adequately the microscopic stochastic properties of radiation which are primarily responsible for their relative effectiveness. Most biophysical models of radiation action now agree that the biological effectiveness of radiations are to a large extent determined by their very localized spatial properties of energy deposition (perhaps DNA and associated structures) and that the probability of residual permanent cellular damage (after cellular repair) depends on the nature of this initial macromolecular damage. Common features of these models make it clear that major future advances in identifying critical physical parameters of radiations for general practical application, or to describe their fundamental mechanisms of action, require accurate knowledge of the spatial patterns of energy deposition down to distances of the order of nanometres. Therefore, adequate descriptions are required of the nature and spatial distribution of the initial charged particles and of the interaction-by-interaction structure of the ensuing charged particle tracks. Recent development and application of Monte Carlo track structure simulations have already made it possible to commence such analyses of radiobiological data. (author). 56 refs, 7 figs

  7. Low level radiation: biological effects

    International Nuclear Information System (INIS)

    Loken, M.K.

    1983-01-01

    It is imperative that physicians and scientists using radiations in health care delivery continue to assess the benefits derived, vs. potential risk, to patients and radiation workers being exposed to radiation in its various forms as part of our health delivery system. Insofar as possible we should assure our patients and ourselves that the benefits outweigh the potential hazards involved. Inferences as to the possible biological effects of low level radiation are generally based on extrapolations from those effects observed and measured following acute exposures to considerably higher doses of radiation. Thus, in order to shed light on the question of the possible biological effects of low level radiation, a wide variety of studies have been carried out using cells in culture and various species of plant and animal life. This manuscript makes reference to some of those studies with indications as to how and why the studies were done and the conclusions that might be drawn there from. In addition reference is made to the handling of this information by scientists, by environmentalists, and by the news media. Unfortunately, in many instances the public has been misled by what has been said and/or written. It is hoped that this presentation will provide an understandable and reasonable perspective on the various appropriate uses of radiation in our lives and how such uses do provide significant improvement in our health and in our quality of life

  8. Biological effects of petroleum hydrocarbons: Predictions of long-term effects and recovery

    International Nuclear Information System (INIS)

    Capuzzo, J.M.

    1990-01-01

    Biological effects of petroleum hydrocarbons on marine organisms and ecosystems are dependent on the persistence and bioavailability of specific hydrocarbons, the ability of organisms to accumulate and metabolize various hydrocarbons, the fate of metabolized products, and the interference of specific hydrocarbons with normal metabolic processes that may alter an organism's chances for survival and reproduction in the environment. In considering the long-term effects of petroleum hydrocarbons on marine ecosystems it is important to ascertain what biological effects may result in subtle ecological changes, changes in community structure and function, and possible impairment of fisheries resources. It is also important to understand which hydrocarbons persist in benthic environments and the sublethal effects that lead to reduced growth, delayed development and reduced reproductive effort, population decline and the loss of that population's function in marine communities. Only through a multi-disciplinary approach to the study of the fate, transport and effects of petroleum hydrocarbons on marine ecosystems will there be a significant improvement in the ability to predict the long-term effects of oil spills and to elucidate the mechanisms of recovery

  9. Performance of honey bee colonies under a long-lasting dietary exposure to sublethal concentrations of the neonicotinoid insecticide thiacloprid.

    Science.gov (United States)

    Siede, Reinhold; Faust, Lena; Meixner, Marina D; Maus, Christian; Grünewald, Bernd; Büchler, Ralph

    2017-07-01

    Substantial honey bee colony losses have occurred periodically in the last decades. The drivers for these losses are not fully understood. The influence of pests and pathogens are beyond dispute, but in addition, chronic exposure to sublethal concentrations of pesticides has been suggested to affect the performance of honey bee colonies. This study aims to elucidate the potential effects of a chronic exposure to sublethal concentrations (one realistic worst-case concentration) of the neonicotinoid thiacloprid to honey bee colonies in a three year replicated colony feeding study. Thiacloprid did not significantly affect the colony strength. No differences between treatment and control were observed for the mortality of bees, the infestation with the parasitic mite Varroa destructor and the infection levels of viruses. No colony losses occurred during the overwintering seasons. Furthermore, thiacloprid did not influence the constitutive expression of the immunity-related hymenoptaecin gene. However, upregulation of hymenoptaecin expression as a response to bacterial challenge was less pronounced in exposed bees than in control bees. Under field conditions, bee colonies are not adversely affected by a long-lasting exposure to sublethal concentrations of thiacloprid. No indications were found that field-realistic and higher doses exerted a biologically significant effect on colony performance. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  10. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Gisone, Pablo; Perez, Maria R.

    2001-01-01

    It has been emphasised the importance of DNA as the main target for ionizing radiation, that can induce damage by its direct action on this molecule or by an indirect effect mediated by free-radicals generated by water radiolysis. Biological effects of ionizing radiation are influenced not only by the dose but also by the dose-rate and the radiation quality. Radiation induced damage, mainly DNA single and double strand breaks, is detected by molecular sensors which in turn trigger signalling cascades leading to cell cycle arrest to allow DNA repair or programmed cell death (apoptosis). Those effects related with cell death, named deterministic, exhibits a dose-threshold below which they are not observed. Acute radiation syndrome and radiological burns are examples of this kind of effects. Other radiation induced effects, called stochastic, are the consequence of cell transformation and do not exhibit a dose-threshold. This is the case of cancer induction and hereditary effects. The aim of this presentation is briefly describe the main aspects of deterministic and stochastic effects from the point of view of radiobiology and radio pathology. (author)

  11. The effect of sublethal injury by heating, freezing, drying and gamma-radiation on the duration of the lag phase of Salmonella typhimurium

    International Nuclear Information System (INIS)

    Mackey, B.M.; Derrick, C.M.

    1982-01-01

    The duration of the lag phase of Salmonella typhimurium surviving heat, freezing, drying and gamma-radiation was used to indicate the time needed to repair sublethal injury. Following equivalent lethal treatments, heat and freeze-injured cells needed longer to repair than those injured by drying or gamma-radiation. Measurement of repair on membrane filters showed that in a heat-injured population having a lag time of 9 h, some individual cells needed up to 14 h to recover maximum tolerance to 3% NaCl. (author)

  12. Toxicokinetic-toxicodynamic modelling of quantal and graded sub-lethal endpoints - a brief discussion of concepts.

    NARCIS (Netherlands)

    Ashauer, R.; Agatz, A.; Albert, C.; Ducrot, V.; Galic, N.; Hendriks, A.J.; Jager, T.; Kretschmann, A.; O'Connor, I.; Rubach, M.N.; Nyman, A.M.; Schmitt, W.; Stadnicka, J.; van den Brink, P.; Preuss, T.G.

    2011-01-01

    We report on the advantages and problems of using toxicokinetic-toxicodynamic (TKTD) models for the analysis, understanding, and simulation of sublethal effects. Only a few toxicodynamic approaches for sublethal effects are available. These differ in their effect mechanism and emphasis on linkages

  13. Effects of salinity on short-term waterborne zinc uptake, accumulation and sub-lethal toxicity in the green shore crab (Carcinus maenas)

    International Nuclear Information System (INIS)

    Niyogi, Som; Blewett, Tamzin A.; Gallagher, Trevor; Fehsenfeld, Sandra; Wood, Chris M.

    2016-01-01

    Highlights: • Zinc accumulation in the euryhaline green crab is partially salinity dependent. • Zinc accumulates mainly in the gills of green crab during acute waterborne exposure. • Branchial zinc and calcium transport in the green crab occurs via a common pathway. • Acute waterborne Zn exposure disrupts calcium and zinc homeostasis in the green crab. - Abstract: Waterborne zinc (Zn) is known to cause toxicity to freshwater animals primarily by disrupting calcium (Ca) homeostasis during acute exposure, but its effects in marine and estuarine animals are not well characterized. The present study investigated the effects of salinity on short-term Zn accumulation and sub-lethal toxicity in the euryhaline green shore crab, Carcinus maenas. The kinetic and pharmacological properties of short-term branchial Zn uptake were also examined. Green crabs (n = 10) were exposed to control (no added Zn) and 50 μM (3.25 mg L"−"1) of waterborne Zn (∼25% of 96 h LC_5_0 in 100 seawater) for 96 h at 3 different salinity regimes (100%, 60% and 20% seawater). Exposure to waterborne Zn increased tissue-specific Zn accumulation across different salinities. However, the maximum accumulation occurred in 20% seawater and no difference was recorded between 60% and 100% seawater. Gills appeared to be the primary site of Zn accumulation, since the accumulation was significantly higher in the gills relative to the hepatopancreas, haemolymph and muscle. Waterborne Zn exposure induced a slight increase in haemolymph osmolality and chloride levels irrespective of salinity. In contrast, Zn exposure elicited marked increases in both haemolymph and gill Ca levels, and these changes were more pronounced in 20% seawater relative to that in 60% or 100% seawater. An in vitro gill perfusion technique was used to examine the characteristics of short-term (1–4 h) branchial Zn uptake over an exposure concentration range of 3–12 μM (200–800 μg L"−"1). The rate of short-term branchial Zn

  14. Effects of salinity on short-term waterborne zinc uptake, accumulation and sub-lethal toxicity in the green shore crab (Carcinus maenas)

    Energy Technology Data Exchange (ETDEWEB)

    Niyogi, Som, E-mail: som.niyogi@usask.ca [Department of Biology, University of Saskatchewan, Saskatoon, SK (Canada); Toxicology Centre, University of Saskatchewan, Saskatoon, SK (Canada); Bamfield Marine Sciences Centre, Bamfield, BC (Canada); Blewett, Tamzin A. [Bamfield Marine Sciences Centre, Bamfield, BC (Canada); Department of Biological Sciences, University of Alberta, Edmonton, AB (Canada); Department of Biology, McMaster University, Hamilton, ON (Canada); Gallagher, Trevor [Toxicology Centre, University of Saskatchewan, Saskatoon, SK (Canada); Fehsenfeld, Sandra [Bamfield Marine Sciences Centre, Bamfield, BC (Canada); Department of Biological Sciences, University of Manitoba, Winnipeg, MB (Canada); Department of Zoology, University of British Columbia, Vancouver, BC (Canada); Wood, Chris M. [Bamfield Marine Sciences Centre, Bamfield, BC (Canada); Department of Biology, McMaster University, Hamilton, ON (Canada); Department of Zoology, University of British Columbia, Vancouver, BC (Canada)

    2016-09-15

    Highlights: • Zinc accumulation in the euryhaline green crab is partially salinity dependent. • Zinc accumulates mainly in the gills of green crab during acute waterborne exposure. • Branchial zinc and calcium transport in the green crab occurs via a common pathway. • Acute waterborne Zn exposure disrupts calcium and zinc homeostasis in the green crab. - Abstract: Waterborne zinc (Zn) is known to cause toxicity to freshwater animals primarily by disrupting calcium (Ca) homeostasis during acute exposure, but its effects in marine and estuarine animals are not well characterized. The present study investigated the effects of salinity on short-term Zn accumulation and sub-lethal toxicity in the euryhaline green shore crab, Carcinus maenas. The kinetic and pharmacological properties of short-term branchial Zn uptake were also examined. Green crabs (n = 10) were exposed to control (no added Zn) and 50 μM (3.25 mg L{sup −1}) of waterborne Zn (∼25% of 96 h LC{sub 50} in 100 seawater) for 96 h at 3 different salinity regimes (100%, 60% and 20% seawater). Exposure to waterborne Zn increased tissue-specific Zn accumulation across different salinities. However, the maximum accumulation occurred in 20% seawater and no difference was recorded between 60% and 100% seawater. Gills appeared to be the primary site of Zn accumulation, since the accumulation was significantly higher in the gills relative to the hepatopancreas, haemolymph and muscle. Waterborne Zn exposure induced a slight increase in haemolymph osmolality and chloride levels irrespective of salinity. In contrast, Zn exposure elicited marked increases in both haemolymph and gill Ca levels, and these changes were more pronounced in 20% seawater relative to that in 60% or 100% seawater. An in vitro gill perfusion technique was used to examine the characteristics of short-term (1–4 h) branchial Zn uptake over an exposure concentration range of 3–12 μM (200–800 μg L{sup −1}). The rate of short

  15. Tritium biological effects and perspective of the biological study

    International Nuclear Information System (INIS)

    Komatsu, Kenshi

    1998-01-01

    Since tritium is an emitter of weak β-rays (5.7keV) and is able to bind to DNA, i.e., the most important genome component, the biological effects should be expected to be more profound than that of X-rays and γ-rays. When carcinogenesis, genetical effects and the detriments for fetus and embryo were used as a biological endpoint, most of tritium RBE (relative biological effectiveness) ranged from 1 to 2. The tritium risk in man could be calculated from these RBEs and γ-ray risk for human exposure, which are obtained mainly from the data on Atomic Bomb survivors. However, the exposure modality from environmental tritium should be a chronic irradiation with ultra low dose rate or a fractionated irradiation. We must estimate the tritium effect in man based on biological experiments alone, due to lack of such epidemiological data. Low dose rate experiment should be always accompanied by the statistical problem of data, since their biological effects are fairy low, and they should involve a possible repair system, such as adaptive response (or hormesis effect) and 'Kada effect' observed in bacteria. Here we discuss future works for the tritium assessment in man, such as (1) developing a high radiation sensitive assay system with rodent hybrid cells containing a single human chromosome and also (2) study on mammal DNA repair at molecular levels using a radiosensitive hereditary disease, Nijmegen Breakage Syndrome. (author)

  16. Sublethal RNA Oxidation as a Mechanism for Neurodegenerative Disease

    Directory of Open Access Journals (Sweden)

    Mark A. Smith

    2008-05-01

    Full Text Available Although cellular RNA is subjected to the same oxidative insults as DNA and other cellular macromolecules, oxidative damage to RNA has not been a major focus in investigations of the biological consequences of free radical damage. In fact, because it is largely single-stranded and its bases lack the protection of hydrogen bonding and binding by specific proteins, RNA may be more susceptible to oxidative insults than is DNA. Oxidative damage to protein-coding RNA or non-coding RNA will, in turn, potentially cause errors in proteins and/or dysregulation of gene expression. While less lethal than mutations in the genome, such sublethal insults to cells might be associated with underlying mechanisms of several chronic diseases, including neurodegenerative disease. Recently, oxidative RNA damage has been described in several neurodegenerative diseases including Alzheimer disease, Parkinson disease, dementia with Lewy bodies, and prion diseases. Of particular interest, oxidative RNA damage can be demonstrated in vulnerable neurons early in disease, suggesting that RNA oxidation may actively contribute to the onset of the disease. An increasing body of evidence suggests that, mechanistically speaking, the detrimental effects of oxidative RNA damage to protein synthesis are attenuated, at least in part, by the existence of protective mechanisms that prevent the incorporation of the damaged ribonucleotides into the translational machinery. Further investigations aimed at understanding the processing mechanisms related to oxidative RNA damage and its consequences may provide significant insights into the pathogenesis of neurodegenerative and other degenerative diseases and lead to better therapeutic strategies.

  17. Lethal and sublethal effects of selected insecticides and an insect growth regulator on the boll weevil (Coleoptera: Curculionidae) ectoparasitoid Catolaccus grandis (Hymenoptera: Pteromalidae).

    Science.gov (United States)

    Elzen, G W; Maldonado, S N; Rojas, M G

    2000-04-01

    A laboratory culture of Catolaccus grandis (Burks), an ectoparasitoid of the boll weevil, Anthonomus grandis grandis Boheman, was exposed to lethal and sublethal doses of insecticides and an insect growth regulator using a spray chamber bioassay. Materials tested were azinphos-methyl, endosulfan, fipronil, malathion, cyfluthrin, dimethoate, spinosad, methyl parathion, acephate, oxamyl, and tebufenozide. At full rates, spinosad was significantly less toxic to female C. grandis than other treatments except endosulfan. Fipronil and malathion were significantly more toxic to females than other treatments. Most of the chemicals tested were highly toxic to male C. grandis; spinosad was least toxic. At reduced rates, most of 4 selected chemicals tested were low in toxicity to C. grandis; however, a reduced rate of malathion was significantly more toxic to females than other treatments. No C. grandis pupae developed from parasitism during a 24-h treatment period with malathion or spinosad. The sex ratio of progeny from sprayed adults appeared to be unaffected by the treatments.

  18. Acute toxicity and sublethal effects of the mixture glyphosate (Roundup® Active and Cosmo-Flux®411F to anuran embryos and tadpoles of four Colombian species

    Directory of Open Access Journals (Sweden)

    Liliana Marcela Henao Muñoz

    2015-03-01

    Full Text Available Glyphosate is the most widely used herbicide in the world with application in agriculture, forestry, industrial weed control, garden and aquatic environments. However, its use is highly controversial for the possible impact on not-target organisms, such as amphibians, which are vanishing at an alarming and rapid rate. Due to the high solubility in water and ionic nature, the glyphosate requires of surfactants to increase activity. In addition, for the control of coca (Erythroxylum coca and agricultural weeds in Colombia, formulated glyphosate is mixed and sprayed with the adjuvant Cosmo-Flux®411F to increase the penetration and activity of the herbicide. This study evaluates the acute toxic and sublethal effects (embryonic development, tadpole body size, tadpole swimming performance of the mixture of the formulated glyphosate Roundup® Active and Cosmo-Flux®411F to anuran embryos and tadpoles of four Colombian species under 96h laboratory standard tests and microcosms, which are more similar to field conditions as they include soil, sand and macrophytes. In the laboratory, embryos and tadpoles of Engystomops pustulosus were the most tolerant (LC50=3 904µg a.e./L; LC50=2 799µg a.e./L, respectively, while embryos and tadpoles of Hypsiboas crepitans (LC50=2 203µg a.e./L; LC50=1 424µg a.e./L, respectively were the most sensitive. R. humboldti and R. marina presented an intermediate toxicity. Embryos were significantly more tolerant to the mixture than tadpoles, which could be likely attributed to the exclusion of chemicals by the embryonic membranes and the lack of organs, such as gills, which are sensitive to surfactants. Sublethal effects were observed for the tadpole body size, but not for the embryonic development and tadpole swimming performance. In microcosms, no toxicity (LC50 could not be estimated, or sublethal responses were observed at concentrations up to fourfold (14.76kg glyphosate a.e./ha the highest field application rate of 3

  19. The biological effectiveness of antiproton irradiation

    DEFF Research Database (Denmark)

    Holzscheiter, Michael H.; Bassler, Niels; Agazaryan, Nzhde

    2006-01-01

    ever measurements of the biological effectiveness of antiprotons. Materials and methods: V79 cells were suspended in a semi-solid matrix and irradiated with 46.7 MeV antiprotons, 48 MeV protons, or 60Co c-rays. Clonogenic survival was determined as a function of depth along the particle beams. Dose...... and particle fluence response relationships were constructed from data in the plateau and Bragg peak regions of the beams and used to assess the biological effectiveness. Results: Due to uncertainties in antiproton dosimetry we defined a new term, called the biologically effective dose ratio (BEDR), which...... has a higher relative biological effectiveness (RBE). Conclusion: We have produced the first measurements of the biological consequences of antiproton irradiation. These data substantiate theoretical predictions of the biological effects of antiproton annihilation within the Bragg peak, and suggest...

  20. Measurement of oxygen enhancement ratio for sub-lethal region using saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Nairy, Rajesha K.; Anjaria, K.B.; Bhat, Nagesh N.; Chaurasia, Rajesh K.; Balakrishnan, Sreedevi; Yerol, Narayana

    2013-01-01

    Oxygen is one of the best known modifiers of radiation sensitivity and the biological effects is greater in the presence of oxygen, and significant modifying effect will be observed only for low LET radiations. The reduced oxygen availability is sensed which trigger homeostatic responses, which impact on virtually all areas of biology and medicine. Failure to achieve complete response following radiotherapy of large tumors is attributed to the presence of radio-resistant hypoxic cells, therefore clarifying the mechanism of the oxygen effect is important. In the present study, a mutant type diploid yeast strain, Saccharomyces cerevisiae D7 was used to study Oxygen Enhancement Ratio (OER) using 60 Co gamma radiation. Cells were washed thrice by centrifugation (2000 g for 5 min) and re-suspended to a cell concentration of 1x108 cells mL-1 in a sterile polypropylene vial for irradiation (sub-lethal dose range, 0-100 Gy). Hypoxic conditions were achieved by incubating the cells in airtight vials at 30℃ for 30 min prior to irradiation. The gene conversion and back mutation analysis were carried out according to the standard protocol. Gene conversion is the radio-sensitive biological endpoint, that can be studied in Saccharomyces cerevisiae D7 yeast cells at trp locus in tryptophan (Trp- medium) deficient medium. The dose response relation at euoxic and hypoxic condition in sub-lethal doses are found to be linear and is represented by Y (Euoxic) = (6.54±0.102) D with R2=0.999 and for hypoxic condition Y(Hypoxic) = (3.346±0.033) D with R2=0.996. The OER can be calculated by dividing the euoxic slope with hypoxic slope, and is 1.95. Back mutation, which is a result of reversion of Isoleucine auxotrophs to prototrophs gives very good information at sub-lethal doses. The dose response relation between back mutated cells and radiation doses at Euoxic and hypoxic condition can be represented as Y(Euoxic) = (2.85±0.126) D with R2= 0.976 and for hypoxic condition Y

  1. Dose-response tests and semi-field evaluation of lethal and sub-lethal effects of slow release pyriproxyfen granules (Sumilarv®0.5G) for the control of the malaria vectors Anopheles gambiae sensu lato.

    Science.gov (United States)

    Mbare, Oscar; Lindsay, Steven W; Fillinger, Ulrike

    2013-03-14

    Recently research has shown that larviciding can be an effective tool for integrated malaria vector control. Nevertheless, the uptake of this intervention has been hampered by the need to re-apply larvicides frequently. There is a need to explore persistent, environmentally friendly larvicides for malaria vector control to reduce intervention efforts and costs by reducing the frequency of application. In this study, the efficacy of a 0.5% pyriproxyfen granule (Surmilarv®0.5G, Sumitomo Chemicals) was assessed for the control of Anopheles gambiae sensu stricto and Anopheles arabiensis, the major malaria vectors in sub-Saharan Africa. Dose-response and standardized field tests were implemented following standard procedures of the World Health Organization's Pesticide Evaluation Scheme to determine: (i) the susceptibility of vectors to this formulation; (ii) the residual activity and appropriate retreatment schedule for field application; and, (iii) sub-lethal impacts on the number and viability of eggs laid by adults after exposure to Sumilarv®0.5G during larval development. Anopheles gambiae s.s. and An. arabiensis were highly susceptible to Sumilarv®0.5G. Estimated emergence inhibition (EI) values were very low and similar for both species. The minimum dosage that completely inhibited adult emergence was between 0.01-0.03 parts per million (ppm) active ingredient (ai). Compared to the untreated control, an application of 0.018 ppm ai prevented 85% (95% confidence interval (CI) 82%-88%) of adult emergence over six weeks under standardized field conditions. A fivefold increase in dosage of 0.09 ppm ai prevented 97% (95% CI 94%-98%) emergence. Significant sub-lethal effects were observed in the standardized field tests. Female An. gambiae s.s. that were exposed to 0.018 ppm ai as larvae laid 47% less eggs, and females exposed to 0.09 ppm ai laid 74% less eggs than females that were unexposed to the treatment. Furthermore, 77% of eggs laid by females exposed to 0

  2. Quantification of biologically effective environmental UV irradiance

    Science.gov (United States)

    Horneck, G.

    To determine the impact of environmental UV radiation on human health and ecosystems demands monitoring systems that weight the spectral irradiance according to the biological responses under consideration. In general, there are three different approaches to quantify a biologically effective solar irradiance: (i) weighted spectroradiometry where the biologically weighted radiometric quantities are derived from spectral data by multiplication with an action spectrum of a relevant photobiological reaction, e.g. erythema, DNA damage, skin cancer, reduced productivity of terrestrial plants and aquatic foodweb; (ii) wavelength integrating chemical-based or physical dosimetric systems with spectral sensitivities similar to a biological response curve; and (iii) biological dosimeters that directly weight the incident UV components of sunlight in relation to the effectiveness of the different wavelengths and to interactions between them. Most biological dosimeters, such as bacteria, bacteriophages, or biomolecules, are based on the UV sensitivity of DNA. If precisely characterized, biological dosimeters are applicable as field and personal dosimeters.

  3. Sublethal Heavy Metal Stress Stimulates Innate Immunity in Tomato

    Directory of Open Access Journals (Sweden)

    Nilanjan Chakraborty

    2015-01-01

    Full Text Available Effect of sublethal heavy metal stress as plant biotic elicitor for triggering innate immunity in tomato plant was investigated. Copper in in vivo condition induced accumulation of defense enzymes like peroxidase (PO, polyphenol oxidase (PPO, phenylalanine ammonia-lyase (PAL, and β-1,3 glucanase along with higher accumulation of total phenol, antioxidative enzymes (catalase and ascorbate peroxidase, and total chlorophyll content. Furthermore, the treatment also induced nitric oxide (NO production which was confirmed by realtime visualization of NO burst using a fluorescent probe 4,5-diaminofluorescein diacetate (DAF-2DA and spectrophotometric analysis. The result suggested that the sublethal dose of heavy metal can induce an array of plant defense responses that lead to the improvement of innate immunity in plants.

  4. The effect of postirradiation holding at 22 degrees C on the repair of sublethal, potentially lethal and potentially neoplastic transforming damage in gamma-irradiated HeLa x skin fibroblast human hybrid cells

    International Nuclear Information System (INIS)

    Redpath, J.L.; Antoniono, R.J.; Mendonca, M.S.; Sun, C.

    1994-01-01

    The effect of postirradiation holding at 22 degrees C on cell growth, progression of cells through the cell cycle, and the repair of sublethal, potentially lethal and potentially neoplastic transforming damage in γ-irradiated HeLa x skin fibroblast human hybrid cells has been examined. Cell growth and cell cycle progression were essentially stopped at this reduced temperature. Cell survival was dramatically reduced by holding confluent cultures for 6 h at 22 degrees C, as opposed to 37 degrees C, after 7.5 Gy γ radiation delivered at a rate of 2 Gy/min. Return of the cells to 37 degrees C for 6 h after holding at 22 degrees C did not result in increased survival. A similar effect was obtained when the cells were held at 22 degrees C between split-dose irradiation of log-phase cultures where no increase in survival was observed over a split-dose interval of 4 h. In this case a partial increase in survival was observed upon returning the cells to 37 degrees C for 3 h after holding at 22 degrees C for the first 3 h of the split-dose interval. Neoplastic transformation frequency was not enhanced by holding confluent cultures for 6 h at 22 degrees C after 7.5 Gy γ radiation. This is consistent with previous observations that misrepair of potentially neoplastic transforming damage already occurs at 37 degrees C. The overall results are interpreted in terms of the reduced temperature favoring misrepair, rather than inhibition of repair, of sublethal, potentially lethal and potentially transforming radiation damage. 24 refs., 5 figs., 3 tabs

  5. Effects of sublethal doses of thiacloprid and its formulation Calypso® on the learning and memory performance of honey bees.

    Science.gov (United States)

    Tison, Léa; Holtz, Sophie; Adeoye, Amy; Kalkan, Önder; Irmisch, Nina S; Lehmann, Nadja; Menzel, Randolf

    2017-10-15

    Learning and memory play a central role in the behavior and communication of foraging bees. We have previously shown that chronic uptake of the neonicotinoid thiacloprid affects the behavior of honey bees in the field. Foraging behavior, homing success, navigation performance and social communication were impaired. Thiacloprid collected at a feeding site at low doses accumulates in foragers over time. Here, we applied a laboratory standard procedure (the proboscis-extension response conditioning) in order to assess which processes, acquisition, memory consolidation and/or memory retrieval were compromised after bees were fed either with thiacloprid or the formulation of thiacloprid named Calypso ® at different sublethal doses. Extinction and generalization tests allowed us to investigate whether bees respond to a learned stimulus, and how selectively. We showed that thiacloprid, as active substance and as formulation, poses a substantial risk to honey bees by disrupting learning and memory functions. These data support and specify the data collected in the field. © 2017. Published by The Company of Biologists Ltd.

  6. Biological effects of high LET radiations

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Masami [Nagasaki Univ. (Japan). Faculty of Pharmaceutical Sciences

    1997-03-01

    Biological effect of radiation is different by a kind of it greatly. Heavy ions were generally more effective in cell inactivation, chromosome aberration induction, mutation induction and neoplastic cell transformation induction than {gamma}-rays in SHE cells. (author)

  7. Lethal and sublethal cellular injury in multifraction irradiation

    International Nuclear Information System (INIS)

    Withers, H.R.

    1975-01-01

    Work has been carried out on cellular injury in multifraction irradiation of mouse tissues and compared with similar work on human skin reported earlier by Dutreix et al (Eur. J. Cancer.; 9:159 (1973)). In agreement with Dutreix et al it is emphasized that the absolute amount of sublethal injury repaired per fractionation interval (Dsub(r)) is not as important to radiotherapists as the change in the amount repaired (ΔDsub(r)) when the dose-per-fraction is altered. It was found that although there is a critical divergence at low doses, the data for mouse tissues are similar to those previously given for human skin and support the conclusions: (i) That the capacity of many normal cells for accumulating and repairing sublethal radiation injury is probably not greatly different. (ii) That fixed exponents used for fraction number and time in iso-effect formulae are inaproporiate. At low doses-per-fraction, repair of sublethal injury is complete, or nearly so, and hence, additional fractionation of dose does not give appreciable additional sparing, whereas rapidly-regenerating tissues, due to the lengthening of overall time, would continue being spared by repopulation. (U.K.)

  8. Effect of cell cycle stage, dose rate and repair of sublethal damage of radiation-induced apoptosis in F9 teratocarcinoma cells

    International Nuclear Information System (INIS)

    Langley, R.E.; Quartuccio, S.G.; Kennealey, P.T.

    1995-01-01

    There are at least two different models of cell death after treatment with ionizing radiation. The first is a failure to undergo sustained cell division despite metabolic survival, and we refer to this end point as open-quotes classical reproductive cell death.close quotes The second is a process that results in loss of cell integrity. This second category includes cellular necrosis as well as apoptosis. Earlier studies in our laboratory showed that the predominant mechanism of cell death for irradiated F9 cell is apoptosis, and there is no indication that these cells die by necrosis. We have therefore used cells of this cell line to reassess basic radiobiological principles with respect to apoptosis. Classical reproductive cell death was determined by staining colonies derived from irradiated cells and scoring colonies of less than 50 cells as reproductively dead and colonies of more than 50 cells as survivors. Cells that failed to produce either type of colony (detached from the plate or disintegrated) were scored as having undergone apoptosis. Using these criteria we found that the fraction of the radiation-killed F9 cells that died by apoptosis did not vary when cells were irradiated at different stages of the cell cycle despite large variations in overall survival. This suggests that the factors that influence radiation sensitivity throughout the cell cycle have an equal impact on apoptosis and classical reproductive cell death. There was no difference in cell survival between split doses and single doses of X rays, suggesting that sublethal damage repair is not a factor in radiation-induced apoptosis of F9 cells. Apoptosis was not affected by changes in dose rate in the range of 0.038-4.96 Gy/min. 48 refs., 6 figs., 1 tab

  9. Magnetic resonance: safety measures and biological effects

    International Nuclear Information System (INIS)

    Gordillo, I.; Lafuente, J.; Fernandez, C.; Barbero, M.J.; Cascon, E.

    1997-01-01

    The biological effects of electromagnetic fields is currently a subject of great controversy. For this reason, magnetic resonance imaging (MRI) and spectroscopy are constantly under investigation. The source of the risk in MRI is associated with the three types of electromagnetic radiation to which the patient is exposed: the static magnetic field, variable (gradient) magnetic fields and radiofrequency fields. Each is capable of producing significant biological effects when employed at sufficient intensity. Patients exposed to risk sources are those situated within the lines of force of the magnetic field, ellipsoid lines that are arranged around the magnet, representing the strength of the surrounding field. To date, at the intensity normally utilized in MRI(<2T) and respecting the field limit recommendations established by the US Food and Drug Administration (FDA) for clinical use of this technique no adverse secondary biological effects have been reported. The known biological effects and other possible secondary effects are reviewed, and the recommended safety measures are discussed. (Author)

  10. Biological Effects of Ionizing Radiation

    International Nuclear Information System (INIS)

    Durand, J.L.

    2000-01-01

    The aim of this work is to verify the existence of the adaptive response phenomenon induced by low doses of ionizing radiation in living cells.A wild-type yeast Saccharomyces cerevisiae (Baker's yeast) was chosen as the biological target.As a parameter to quantify the sensibility of the target to radiation, the Lethal Dose 50 (LD50 ) was observed. In our experimental condition a value of (60 ± 1) Gy was measured for LD50 with Dose Rate of (0.44 ± 0.03) Gy/min. The method employed to show up the adaptive response phenomenon consisted in exposing the sample to low ''conditioning'' doses, which would initiate these mechanisms. Later the samples with and without conditioning were exposed to higher ''challenging'' doses (such as LD50), and the surviving fractions were compared. In order to maximize the differences, the doses and the time between irradiations were varied. The best results were obtained with both a conditioning dose of (0.44 ± 0.03) Gy and a waiting time of 2 hs until the application of the challenging dose. Following this procedures the 80% of the conditioned samples has survived, after receiving the application of the LD50. The adaptive response phenomenon was also verified for a wide range of challenging doses

  11. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Experiments with small animals, tissue cultures, and inanimate materials help with understanding the effects of ionizing radiation that occur at the molecular level and cause the gross effects observed in man. Topics covered in this chapter include the following: Radiolysis of Water; Radiolysis of Organic Compounds; Radiolysis in Cells; Radiation Exposure and Dose Units; Dose Response Curves; Radiation Effects in Animals; Factors Affecting Health Risks. 8 refs., 3 figs., 5 tabs

  12. Biological effects of nuclear radiation

    International Nuclear Information System (INIS)

    Hotz, G.

    1975-01-01

    After a brief survey about the main radiobiological effects caused by ionizing radiation, human symptoms after irradiation and incorporation are shown. The special radiotoxic effect of radionuclides which are chemically associated with metabolism-specific elements such as calcium and potassium is shown and methods of treatment are indicated. (ORU) [de

  13. Sublethal effects of a chlorinated and heated effluent on the physiology of the mussel, Mytilus edulis L.: A reduction in fitness for survival?

    International Nuclear Information System (INIS)

    Mazik, Krysia; Hitchman, Natasha; Quintino, Victor; Taylor, Colin J.L.; Butterfield, Jonathan; Elliott, Michael

    2013-01-01

    Highlights: • The impact of chlorinated cooling water effluent on Scope for Growth was assessed. • Scope for Growth in mussels was reduced after exposure to effluent in the field. • Scope for Growth was reduced along an exposure gradient, most notably in summer. • Body condition and reproductive condition decreased along a gradient of exposure. • Negative physiological effects were contained within a 1 km radius of the discharge. -- Abstract: Coastal power stations entrain large volumes of cooling water, requiring biocidal treatment to prevent biological fouling. Discharged effluent is both heated and contaminated with residual traces of biocide and so it is necessary to quantify the impacts of this discharge. Cooling water from Heysham 2 nuclear power station, NW England, UK, is discharged to the intertidal area, via a culvert (to minimise erosion and maximise dilution and dispersion by directing the effluent into the receiving water at all states of the tide) within which the effluent is contained at low water. The culvert and surrounding coastal area support a population of blue mussels (Mytilus edulis). Mussel health was determined along a gradient of exposure, using three physiological indices: Scope for Growth, Gonad Mantle Index and Somatic Condition Index (K Factor). The Mussels within the culvert exhibited reduced physiological index values compared to an external site. A trend was identified down the length of the culvert, representing a gradient of exposure and indicating a potential negative effect on growth and reproductive output

  14. Biological effects of high-energy radiation

    International Nuclear Information System (INIS)

    Curtis, S.B.

    1976-01-01

    The biological effects of high-energy radiation are reviewed, with emphasis on the effects of the hadronic component. Proton and helium ion effects are similar to those of the more conventional and sparsely ionizing x- and γ-radiation. Heavy-ions are known to be more biologically effective, but the long term hazard from accumulated damage has yet to be assessed. Some evidence of widely varying but dramatically increased effectiveness of very high-energy (approximately 70 GeV) hadron beams is reviewed. Finally, the importance of the neutron component in many situations around high-energy accelerators is pointed out

  15. Biological effects of ionising radiation

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    The paper reports the proceedings of a conference organised jointly by Friends of the Earth (U.K.) and Greenpeace (International). The aim of the conference was to discuss the effects of low level radiation, particularly on man, within the terms of dose/risk relationships. The topics discussed included: sources of radiation, radiation discharges from nuclear establishments, predictive modelling of radiation hazards, radiation effects at Hiroshima, low dose effects and ICRP dose limits, variation in sensitivity to radiation, and the link between childhood cancer and nuclear power. (U.K.)

  16. [Side effects of biologic therapies in psoriasis].

    Science.gov (United States)

    Altenburg, A; Augustin, M; Zouboulis, C C

    2018-04-01

    The introduction of biologics has revolutionized the treatment of moderate to severe plaque psoriasis. Due to the continuous expansion of biological therapies for psoriasis, it is particularly important to acknowledge efficacy and safety of the compounds not only in clinical trials but also in long-term registry-based observational studies. Typical side effects and significant risks of antipsoriatic biologic therapies considering psoriatic control groups are presented. A selective literature search was conducted in PubMed and long-term safety studies of the psoriasis registries PsoBest, PSOLAR and BADBIR were evaluated. To assess the long-term safety of biologics, the evaluation of the course of large patient cohorts in long-term registries is of particular medical importance. Newer biologic drugs seem to exhibit a better safety profile than older ones.

  17. Biological effects of electromagnetic fields

    African Journals Online (AJOL)

    2012-02-28

    Feb 28, 2012 ... radiofrequency emitting sources are radars, mobile phones and their base stations, ... and industrial applications, could have effect on living organisms. ...... Hazards of Electromagnetic Pollution (Msc Thesis). Department of ...

  18. The biological effectiveness of antiproton irradiation

    International Nuclear Information System (INIS)

    Holzscheiter, Michael H.; Bassler, Niels; Agazaryan, Nzhde; Beyer, Gerd; Blackmore, Ewart; DeMarco, John J.; Doser, Michael; Durand, Ralph E.; Hartley, Oliver; Iwamoto, Keisuke S.; Knudsen, Helge V.; Landua, Rolf; Maggiore, Carl; McBride, William H.; Moller, Soren Pape; Petersen, Jorgen; Skarsgard, Lloyd D.; Smathers, James B.; Solberg, Timothy D.; Uggerhoj, Ulrik I.; Vranjes, Sanja; Withers, H. Rodney; Wong, Michelle; Wouters, Bradly G.

    2006-01-01

    Background and purpose: Antiprotons travel through tissue in a manner similar to that for protons until they reach the end of their range where they annihilate and deposit additional energy. This makes them potentially interesting for radiotherapy. The aim of this study was to conduct the first ever measurements of the biological effectiveness of antiprotons. Materials and methods: V79 cells were suspended in a semi-solid matrix and irradiated with 46.7 MeV antiprotons, 48 MeV protons, or 6 Co γ-rays. Clonogenic survival was determined as a function of depth along the particle beams. Dose and particle fluence response relationships were constructed from data in the plateau and Bragg peak regions of the beams and used to assess the biological effectiveness. Results: Due to uncertainties in antiproton dosimetry we defined a new term, called the biologically effective dose ratio (BEDR), which compares the response in a minimally spread out Bragg peak (SOBP) to that in the plateau as a function of particle fluence. This value was ∼3.75 times larger for antiprotons than for protons. This increase arises due to the increased dose deposited in the Bragg peak by annihilation and because this dose has a higher relative biological effectiveness (RBE). Conclusion: We have produced the first measurements of the biological consequences of antiproton irradiation. These data substantiate theoretical predictions of the biological effects of antiproton annihilation within the Bragg peak, and suggest antiprotons warrant further investigation

  19. Impacts of Sublethal Mercury Exposure on Birds: A Detailed Review.

    Science.gov (United States)

    Whitney, Margaret C; Cristol, Daniel A

    Mercury is a ubiquitous environmental contaminant known to accumulate in, and negatively affect, fish-eating and oceanic bird species, and recently demonstrated to impact some terrestrial songbirds to a comparable extent. It can bioaccumulate to concentrations of >1 μg/g in tissues of prey organisms such as fish and insects. At high enough concentrations, exposure to mercury is lethal to birds. However, environmental exposures are usually far below the lethal concentrations established by dosing studies.The objective of this review is to better understand the effects of sublethal exposure to mercury in birds. We restricted our survey of the literature to studies with at least some exposures >5 μg/g. The majority of sublethal effects were subtle and some studies of similar endpoints reached different conclusions. Strong support exists in the literature for the conclusion that mercury exposure reduces reproductive output, compromises immune function, and causes avoidance of high-energy behaviors. For some endpoints, notably certain measures of reproductive success, endocrine and neurological function, and body condition, there is weak or contradictory evidence of adverse effects and further study is required. There was no evidence that environmentally relevant mercury exposure affects longevity, but several of the sublethal effects identified likely do result in fitness reductions that could adversely impact populations. Overall, 72% of field studies and 91% of laboratory studies found evidence of deleterious effects of mercury on some endpoint, and thus we can conclude that mercury is harmful to birds, and the many effects on reproduction indicate that bird population declines may already be resulting from environmental mercury pollution.

  20. Biological effects of proton radiation: an update

    International Nuclear Information System (INIS)

    Girdhani, S.; Hlatky, L.; Sachs, R.

    2015-01-01

    Proton radiation provides significant dosimetric advantages when compared with gamma radiation due to its superior energy deposition characteristics. Although the physical aspects of proton radiobiology are well understood, biological and clinical endpoints are understudied. The current practice to assume the relative biological effectiveness of low linear energy transfer (LET) protons to be a generic value of about 1.1 relative to photons likely obscures important unrecognised differentials in biological response between these radiation qualities. A deeper understanding of the biological properties induced by proton radiation would have both radiobiological and clinical impact. This article briefly points to some of the literature pertinent to the effects of protons on tissue-level processes that modify disease progression, such as angiogenesis, cell invasion and cancer metastasis. Recent findings hint that proton radiation may, in addition to offering improved radio-therapeutic targeting, be a means to provide a new dimension for increasing therapeutic benefits for patients by manipulating these tissue-level processes. (authors)

  1. Dose–response tests and semi-field evaluation of lethal and sub-lethal effects of slow release pyriproxyfen granules (Sumilarv®0.5G) for the control of the malaria vectors Anopheles gambiae sensu lato

    Science.gov (United States)

    2013-01-01

    Background Recently research has shown that larviciding can be an effective tool for integrated malaria vector control. Nevertheless, the uptake of this intervention has been hampered by the need to re-apply larvicides frequently. There is a need to explore persistent, environmentally friendly larvicides for malaria vector control to reduce intervention efforts and costs by reducing the frequency of application. In this study, the efficacy of a 0.5% pyriproxyfen granule (Surmilarv®0.5G, Sumitomo Chemicals) was assessed for the control of Anopheles gambiae sensu stricto and Anopheles arabiensis, the major malaria vectors in sub-Saharan Africa. Methods Dose–response and standardized field tests were implemented following standard procedures of the World Health Organization’s Pesticide Evaluation Scheme to determine: (i) the susceptibility of vectors to this formulation; (ii) the residual activity and appropriate retreatment schedule for field application; and, (iii) sub-lethal impacts on the number and viability of eggs laid by adults after exposure to Sumilarv®0.5G during larval development. Results Anopheles gambiae s.s. and An. arabiensis were highly susceptible to Sumilarv®0.5G. Estimated emergence inhibition (EI) values were very low and similar for both species. The minimum dosage that completely inhibited adult emergence was between 0.01-0.03 parts per million (ppm) active ingredient (ai). Compared to the untreated control, an application of 0.018 ppm ai prevented 85% (95% confidence interval (CI) 82%-88%) of adult emergence over six weeks under standardized field conditions. A fivefold increase in dosage of 0.09 ppm ai prevented 97% (95% CI 94%-98%) emergence. Significant sub-lethal effects were observed in the standardized field tests. Female An. gambiae s.s. that were exposed to 0.018 ppm ai as larvae laid 47% less eggs, and females exposed to 0.09 ppm ai laid 74% less eggs than females that were unexposed to the treatment. Furthermore, 77

  2. Biological Effects of Electromagnetic Fields

    Science.gov (United States)

    2006-11-27

    Warning stimuli, as well as learning material, i.e. the numbers to recall, were presented binaurally via earphones at an intensity of 65dB sound...ensued in a remarkable increase in the yield of ES-derived spontaneously beating cardiomyocytes. Figure 3 Effect of MF on...move the mucus along a surface layer of saline. This is very likely that the cilia, beating with the frequency about few tenth of Hertz, generate some

  3. Assessment of Mercury Bioaccumulation in Zebra Cichlid (Cichlasoma Nigrofasciatum Exposed to Sublethal Concentrations of Permethrin

    Directory of Open Access Journals (Sweden)

    Mahdi Banaee

    2014-12-01

    Full Text Available Background: Aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. Mercury is a toxic metal with no known biological benefit to organisms. Bioavailability of mercury in aquatic environments depends on biological and non-biological parameters including other pollutants. Therefore, the objectives of this research were to determine the effects of permethrin on bioaccumulation of mercury in zebra cichlid. Methods: Acute toxicity (LC50 of permethrin and mercury chloride was evaluated by estimating mortality in Probit Model in SPSS (version 19.0 IBM. In sub-lethal toxicity, zebra cichlid (Cichlasoma nigrofasciatum was exposed to various concentrations of permethrin (0.0, 0.40, 0.80, 1.20 and 1.60 µg.L-1 combined with 20 µg.L-1 mercury chloride for 15 days. At the end of the experiment, mercury concentrations were measured using ICP-OES-Perkin elmer (optima 7300-DV. Results: 96 h LC50 values of permethrin and mercury for C. nigrofasciatum were calculated to be 17.55 µg.L-1 and 140.38 µg.L-1, respectively. Our results clearly showed that the bioaccumulation of mercury in the specimens increased with increasing concentrations of permethrin to 1.20 and 1.60 µg.L-1. Conclusion: Increasing the concentration of permethrin had synergistic effects on the bioaccumulation of mercury in fish.

  4. Biological effects of prenatal irradiation

    International Nuclear Information System (INIS)

    Streffer, Christian

    1997-01-01

    After large releases of radionuclides, exposure of the embryo or fetus can take place by external irradiation or uptake of radionuclies. The embryo and fetus are radiosensitive throughout prenatal development. The quality and extent of radiation effects depend on the development stage. During the preimplantation period (one to 10 days postconception, p.c.) a radiation exposure of at least 0.2 Gy can cause the death of the embryo. Malformations are only observed in rare cases when genetic predisposition exist. Macroscopic, anatomical malformations are induced only after irradiation during the major organogenesis (two to eight weeks p.c.). A radiation dose of about 0.2 Gy is a doubling dose for the malformation risks as extrapolated from experiments with rodents. The human embryo may be more radioresistant. During early fetogenesis (8-15 weeks p.c.) a high radiosensitivity exists for the developmental of the brain. Radiation doses of 1.0 Gy cause severe mental retardation in about 40% of the exposed fetuses. It must be taken into account that a radiation exposure during the fetal period can also induce cancer. It is generally assumed that the risk exists at about the same level as for children. (Author)

  5. Biological Effects Of Artificial Illumination

    Science.gov (United States)

    Corth, Richard

    1980-10-01

    We are increasingly being warned of the possible effects of so called "polluted" light, that is light that differs in spectral content from that of sunlight. We should be concerned, we are told, because all animals and plants have evolved under this natural daylight and therefore any difference between that illuminant and the artificial illuminants that are on the market today, is suspect. The usual presentation of the differences between the sunlight and the artificial illuminants are as shown in Figure 1. Here we are shown the spectral power distribution of sunlight and Cool White fluorescent light. The spectral power distributions of each have been normalized to some convenient wavelength so that each can be seen and easily compared on the same figure. But this presentation is misleading for one does not experience artificial illuminants at the same intensity as one experiences sunlight. Sunlight intensities are ordinarily found to be in the 8000 to 10,000 footcandle range whereas artificial illuminants are rarely experienced at intensity levels greater than 100 footcandles. Therefore a representative difference between the two types of illumination conditions is more accurately represented as in Figure 2. Thus if evolutionary adaptations require that humans and other animals be exposed to sunlight to ensure wellbeing, it is clear that one must be exposed to sunlight intensities. It is not feasible to expect that artificially illuminated environments will be lit to the same intensity as sunlight

  6. The Picture Superiority Effect and Biological Education.

    Science.gov (United States)

    Reid, D. J.

    1984-01-01

    Discusses learning behaviors where the "picture superiority effect" (PSE) seems to be most effective in biology education. Also considers research methodology and suggests a new research model which allows a more direct examination of the strategies learners use when matching up picture and text in efforts to "understand"…

  7. Biological effects on the source of geoneutrinos

    DEFF Research Database (Denmark)

    Sleep, Norman H.; Bird, Dennis K.; Rosing, Minik Thorleif

    2013-01-01

    its bulk earth value of similar to 4; Pb isotope measurements on mantle-derived rocks yield low Th/U values, effectively averaged over geological time. The physics of the modern biological process is complicated, but the net effect is that much of the U in the mantle comes from subducted marine...

  8. The relative biological effectiveness of antiprotons

    DEFF Research Database (Denmark)

    Holzscheiter, Michael H.; Alsner, Jan; Bassler, Niels

    2016-01-01

    Background and purpose: Aside from the enhancement of physical dose deposited by antiprotons annihilating in tissue-like material compared to protons of the same range a further increase of biological effective dose has been demonstrated. This enhancement can be expressed in an increase of the re......Background and purpose: Aside from the enhancement of physical dose deposited by antiprotons annihilating in tissue-like material compared to protons of the same range a further increase of biological effective dose has been demonstrated. This enhancement can be expressed in an increase...... of the relative biological effectiveness (RBE) of antiprotons near the end of range. We have performed the first-ever direct measurement of the RBE of antiprotons both at rest and in flight. Materials and methods: Experimental data were generated on the RBE of an antiproton beam entering a tissue-like target...

  9. Biological Effects of Low-Dose Exposure

    CERN Document Server

    Komochkov, M M

    2000-01-01

    On the basis of the two-protection reaction model an analysis of stochastic radiobiological effects of low-dose exposure of different biological objects has been carried out. The stochastic effects are the results published in the last decade: epidemiological studies of human cancer mortality, the yield of thymocyte apoptosis of mice and different types of chromosomal aberrations. The results of the analysis show that as dependent upon the nature of biological object, spontanous effect, exposure conditions and radiation type one or another form dose - effect relationship is realized: downwards concave, near to linear and upwards concave with the effect of hormesis included. This result testifies to the incomplete conformity of studied effects of 1990 ICRP recomendations based on the linear no-threshold hypothesis about dose - effect relationship. Because of this the methodology of radiation risk estimation recomended by ICRP needs more precisian and such quantity as collective dose ought to be classified into...

  10. Recurrent sublethal warming reduces embryonic survival, inhibits juvenile growth, and alters species distribution projections under climate change.

    Science.gov (United States)

    Carlo, Michael A; Riddell, Eric A; Levy, Ofir; Sears, Michael W

    2018-01-01

    The capacity to tolerate climate change often varies across ontogeny in organisms with complex life cycles. Recently developed species distribution models incorporate traits across life stages; however, these life-cycle models primarily evaluate effects of lethal change. Here, we examine impacts of recurrent sublethal warming on development and survival in ecological projections of climate change. We reared lizard embryos in the laboratory under temperature cycles that simulated contemporary conditions and warming scenarios. We also artificially warmed natural nests to mimic laboratory treatments. In both cases, recurrent sublethal warming decreased embryonic survival and hatchling sizes. Incorporating survivorship results into a mechanistic species distribution model reduced annual survival by up to 24% compared to models that did not incorporate sublethal warming. Contrary to models without sublethal effects, our model suggests that modest increases in developmental temperatures influence species ranges due to effects on survivorship. © 2017 John Wiley & Sons Ltd/CNRS.

  11. Biological effect of radionuclides on plants

    International Nuclear Information System (INIS)

    Prister, B.S.; Khal'chenko, V.A.; Polyakova, V.Y.; Shevchenko, V.A.; Shejn, G.P.; Aleksakhin, R.M.

    1979-01-01

    Stated are dosimetry principles and given is an analysis of biological radionuclide effect on plants in aerial and root intakes. A comparative barley radiosensitivity characteristic depending on plant development phases during irradiation is given using LD 50 criteria. Considered is a possibility for using generalized bioinformation parameters as sensitive indications for estimating biological effects due to the influence of low radiation doses. On the grounds of data obtained generalization are forecasted probable losses of crops when getting radionuclides into plants during various vegetation periods

  12. Ionising radiation - physical and biological effects

    International Nuclear Information System (INIS)

    Holter, Oe.; Ingebretsen, F.; Parr, H.

    1979-01-01

    The physics of ionising radiation is briefly presented. The effects of ionising radiation on biological cells, cell repair and radiosensitivity are briefly treated, where after the effects on man and mammals are discussed and related to radiation doses. Dose limits are briefly discussed. The genetic effects are discussed separately. Radioecology is also briefly treated and a table of radionuclides deriving from reactors, and their radiation is given. (JIW)

  13. Biological effectiveness of neutrons: Research needs

    Energy Technology Data Exchange (ETDEWEB)

    Casarett, G.W.; Braby, L.A.; Broerse, J.J.; Elkind, M.M.; Goodhead, D.T.; Oleinick, N.L.

    1994-02-01

    The goal of this report was to provide a conceptual plan for a research program that would provide a basis for determining more precisely the biological effectiveness of neutron radiation with emphasis on endpoints relevant to the protection of human health. This report presents the findings of the experts for seven particular categories of scientific information on neutron biological effectiveness. Chapter 2 examines the radiobiological mechanisms underlying the assumptions used to estimate human risk from neutrons and other radiations. Chapter 3 discusses the qualitative and quantitative models used to organize and evaluate experimental observations and to provide extrapolations where direct observations cannot be made. Chapter 4 discusses the physical principles governing the interaction of radiation with biological systems and the importance of accurate dosimetry in evaluating radiation risk and reducing the uncertainty in the biological data. Chapter 5 deals with the chemical and molecular changes underlying cellular responses and the LET dependence of these changes. Chapter 6, in turn, discusses those cellular and genetic changes which lead to mutation or neoplastic transformation. Chapters 7 and 8 examine deterministic and stochastic effects, respectively, and the data required for the prediction of such effects at different organizational levels and for the extrapolation from experimental results in animals to risks for man. Gaps and uncertainties in this data are examined relative to data required for establishing radiation protection standards for neutrons and procedures for the effective and safe use of neutron and other high-LET radiation therapy.

  14. Biological effectiveness of neutrons: Research needs

    International Nuclear Information System (INIS)

    Casarett, G.W.; Braby, L.A.; Broerse, J.J.; Elkind, M.M.; Goodhead, D.T.; Oleinick, N.L.

    1994-02-01

    The goal of this report was to provide a conceptual plan for a research program that would provide a basis for determining more precisely the biological effectiveness of neutron radiation with emphasis on endpoints relevant to the protection of human health. This report presents the findings of the experts for seven particular categories of scientific information on neutron biological effectiveness. Chapter 2 examines the radiobiological mechanisms underlying the assumptions used to estimate human risk from neutrons and other radiations. Chapter 3 discusses the qualitative and quantitative models used to organize and evaluate experimental observations and to provide extrapolations where direct observations cannot be made. Chapter 4 discusses the physical principles governing the interaction of radiation with biological systems and the importance of accurate dosimetry in evaluating radiation risk and reducing the uncertainty in the biological data. Chapter 5 deals with the chemical and molecular changes underlying cellular responses and the LET dependence of these changes. Chapter 6, in turn, discusses those cellular and genetic changes which lead to mutation or neoplastic transformation. Chapters 7 and 8 examine deterministic and stochastic effects, respectively, and the data required for the prediction of such effects at different organizational levels and for the extrapolation from experimental results in animals to risks for man. Gaps and uncertainties in this data are examined relative to data required for establishing radiation protection standards for neutrons and procedures for the effective and safe use of neutron and other high-LET radiation therapy

  15. Estimation of Biological Effects of Tritium.

    Science.gov (United States)

    Umata, Toshiyuki

    2017-01-01

    Nuclear fusion technology is expected to create new energy in the future. However, nuclear fusion requires a large amount of tritium as a fuel, leading to concern about the exposure of radiation workers to tritium beta radiation. Furthermore, countermeasures for tritium-polluted water produced in decommissioning of the reactor at Fukushima Daiichi Nuclear Power Station may potentially cause health problems in radiation workers. Although, internal exposure to tritium at a low dose/low dose rate can be assumed, biological effect of tritium exposure is not negligible, because tritiated water (HTO) intake to the body via the mouth/inhalation/skin would lead to homogeneous distribution throughout the whole body. Furthermore, organically-bound tritium (OBT) stays in the body as parts of the molecules that comprise living organisms resulting in long-term exposure, and the chemical form of tritium should be considered. To evaluate the biological effect of tritium, the effect should be compared with that of other radiation types. Many studies have examined the relative biological effectiveness (RBE) of tritium. Hence, we report the RBE, which was obtained with radiation carcinogenesis classified as a stochastic effect, and serves as a reference for cancer risk. We also introduce the outline of the tritium experiment and the principle of a recently developed animal experimental system using transgenic mouse to detect the biological influence of radiation exposure at a low dose/low dose rate.

  16. Biologic effects of electromagnetic radiation and microwave

    International Nuclear Information System (INIS)

    Deng Hua

    2002-01-01

    Electromagnetic radiation and microwave exist mankind's environment widely. People realize they disserve authors' health when authors make use of them. Electromagnetic radiation is one of the major physic factors which injure people's health. A review of the biologic mechanism about electromagnetic radiation and microwave, their harmful effects to human body, problems in authors' research and the prospect

  17. Biological radiation effects and radioprotection standards

    International Nuclear Information System (INIS)

    Clerc, H.

    1991-03-01

    In this report, after recalling the mode of action of ionizing radiations, the notions of dose, dose equivalents and the values of natural irradiation, the author describes the biological radiation effects. Then he presents the ICRP recommendations and their applications to the french radioprotection system

  18. Study of biological effect of radiation

    International Nuclear Information System (INIS)

    Li Guisheng

    1992-01-01

    The some progress on the study of biological effect for protract exposure to low dose rate radiation is reported, and it is indicated that the potential risk of this exposure for the human health and the importance of the routine monitoring of radiation dose for various nuclear installations. The potential exposure to the low dose rate radiation would attract people's extra attention

  19. BIOLOGIC AND ECONOMIC EFFECTS OF INCLUDING DIFFERENT ...

    African Journals Online (AJOL)

    The biologic and economic effects of including three agro-industrial by-products as ingredients in turkey poult diets were investigated using 48 turkey poults in a completely randomised design experiment. Diets were formulated to contain the three by-products – wheat offal, rice husk and palm kernel meal, each at 20% level ...

  20. Sublethal Dosage of Imidacloprid Reduces the Microglomerular Density of Honey Bee Mushroom Bodies

    Science.gov (United States)

    Peng, Yi-Chan; Yang, En-Cheng

    2016-01-01

    The dramatic loss of honey bees is a major concern worldwide. Previous studies have indicated that neonicotinoid insecticides cause behavioural abnormalities and have proven that exposure to sublethal doses of imidacloprid during the larval stage decreases the olfactory learning ability of adults. The present study shows the effect of sublethal doses of imidacloprid on the neural development of the honey bee brain by immunolabelling synaptic units in the calyces of mushroom bodies. We found that the density of the synaptic units in the region of the calyces, which are responsible for olfactory and visual functions, decreased after being exposed to a sublethal dose of imidacloprid. This not only links a decrease in olfactory learning ability to abnormal neural connectivity but also provides evidence that imidacloprid damages the development of the nervous system in regions responsible for both olfaction and vision during the larval stage of the honey bee. PMID:26757950

  1. Nuclear energy: biological effects and environmental impact

    International Nuclear Information System (INIS)

    Boonefaes, M.

    1987-01-01

    This thesis is concerned with the large development of nuclear power plants and the recent nuclear catastrophe which has made clear how the hazards resulting from radioactivity affect public health and the environment. Environmental effects of nuclear power plants operating in normal conditions are small, but to obtain nuclear power plants of reduced radioactivity, optimization of their design, construction, operation and waste processing plays a decisive role. Biological effects of ionizing radiations and environmental impacts of Nuclear Power plants are developed [fr

  2. Functional modifications of macrophage activity after sublethal irradiation

    International Nuclear Information System (INIS)

    Swartz, R.P.

    1982-01-01

    The modifications of macrophage activity following sublethal irradiation, both in vivo and in vitro, were studied using spreading and C3b-receptor-mediated ingestion assays. Nonelicited peritoneal washout cells were examined for changes in activity and selected population characteristics. The cells from irradiated mice were from a resident peritoneal population and not immigrating cells. The macrophage population showed enhanced activity early with a refractory period (24-48) when the macrophages were unresponsive to stimulation by irradiated lymphocytes. The enhanced activity was inversely dose dependent on macrophage. The lymphocytes showed a regulatory function(s) on the time post irradiation at which they were examined. Early lymphocytes exhibited the ability to enhance the activity of normal macrophages while lymphocytes removed 24 hours post irradiation could suppress the activity of already activated macrophages. The effect(s) of the various lymphocyte populations were reproduced with cell-free supernatants which was indicative of the production of lymphokines. Separation on nylon wool columns indicated that the activity resided primarily in the T-cell population of lymphocytes. In vitro irradiation indicated that stimulation of the lymphocytes is macrophage dependent. Additional work indicated that sublethally irradiated macrophages did not inhibit replication of the coccidian protozoon Toxoplasma gondii although they did show increased phagocytosis. Examination of the serum from whole body irradiated mice showed the presence of a postirradiation substance which enhanced the phagocytosis of normal macrophages. It was not present in the serum of normal mice and was not endotoxin

  3. Lunar biological effects and the magnetosphere.

    Science.gov (United States)

    Bevington, Michael

    2015-12-01

    The debate about how far the Moon causes biological effects has continued for two millennia. Pliny the Elder argued for lunar power "penetrating all things", including plants, fish, animals and humans. He also linked the Moon with tides, confirmed mathematically by Newton. A review of modern studies of biological effects, especially from plants and animals, confirms the pervasive nature of this lunar force. However calculations from physics and other arguments refute the supposed mechanisms of gravity and light. Recent space exploration allows a new approach with evidence of electromagnetic fields associated with the Earth's magnetotail at full moon during the night, and similar, but more limited, effects from the Moon's wake on the magnetosphere at new moon during the day. The disturbance of the magnetotail is perhaps shown by measurements of electric fields of up to 16V/m compared with the usual lunar biological effects, such as acute myocardial infarction, could help the development of strategies to reduce adverse effects for people sensitive to geomagnetic disturbance. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Progranulin and its biological effects in cancer.

    Science.gov (United States)

    Arechavaleta-Velasco, Fabian; Perez-Juarez, Carlos Eduardo; Gerton, George L; Diaz-Cueto, Laura

    2017-11-07

    Cancer cells have defects in regulatory mechanisms that usually control cell proliferation and homeostasis. Different cancer cells share crucial alterations in cell physiology, which lead to malignant growth. Tumorigenesis or tumor growth requires a series of events that include constant cell proliferation, promotion of metastasis and invasion, stimulation of angiogenesis, evasion of tumor suppressor factors, and avoidance of cell death pathways. All these events in tumor progression may be regulated by growth factors produced by normal or malignant cells. The growth factor progranulin has significant biological effects in different types of cancer. This protein is a regulator of tumorigenesis because it stimulates cell proliferation, migration, invasion, angiogenesis, malignant transformation, resistance to anticancer drugs, and immune evasion. This review focuses on the biological effects of progranulin in several cancer models and provides evidence that this growth factor should be considered as a potential biomarker and target in cancer treatment.

  5. THz waves: biological effects, industrial and medical

    International Nuclear Information System (INIS)

    Coutaz, J.L.; Garet, F.; Le Drean, Y.; Zhadobov, M.; Veyret, B.; Mounaix, P.; Caumes, J.P.; Gallot, G.; Gian Piero, Gallerano; Mouret, G.; Guilpin, J.C.

    2011-01-01

    Following the debates about body scanners installed in airports for passengers security control, the non-ionizing radiations (NIR) section of the French radiation protection society (SFR) has organized a conference day to take stock of the present day knowledge about the physical aspects and the biological effects of this frequency range as well as about their medical, and industrial applications (both civil and military). This document gathers the slides of the available presentations: 1 - introduction and general considerations about THz waves, the THz physical phenomenon among NIR (J.L. Coutaz); 2 - interaction of millimeter waves with living material: from dosimetry to biological impacts (Y. Le Drean and M. Zhadobov); 3 - Tera-Hertz: standards and recommendations (B. Veyret); 4 - THz spectro-imaging technique: status and perspectives (P. Mounaix); 5 - THz technology: seeing the invisible? (J.P. Caumes); 6 - Tera-Hertz: biological and medical applications (G. Gallot); 7 - Biological applications of THz radiation: a review of events and a glance to the future (G.P. Gallerano); 8 - Industrial and military applications - liquids and solids detection in the THz domain (F. Garet); 9 - THz radiation and its civil and military applications - gas detection and quantifying (G. Mouret); 10 - Body scanners and civil aviation security (J.C. Guilpin, presentation not available). (J.S.)

  6. Electromagnetic effects - From cell biology to medicine.

    Science.gov (United States)

    Funk, Richard H W; Monsees, Thomas; Ozkucur, Nurdan

    2009-01-01

    In this review we compile and discuss the published plethora of cell biological effects which are ascribed to electric fields (EF), magnetic fields (MF) and electromagnetic fields (EMF). In recent years, a change in paradigm took place concerning the endogenously produced static EF of cells and tissues. Here, modern molecular biology could link the action of ion transporters and ion channels to the "electric" action of cells and tissues. Also, sensing of these mainly EF could be demonstrated in studies of cell migration and wound healing. The triggers exerted by ion concentrations and concomitant electric field gradients have been traced along signaling cascades till gene expression changes in the nucleus. Far more enigmatic is the way of action of static MF which come in most cases from outside (e.g. earth magnetic field). All systems in an organism from the molecular to the organ level are more or less in motion. Thus, in living tissue we mostly find alternating fields as well as combination of EF and MF normally in the range of extremely low-frequency EMF. Because a bewildering array of model systems and clinical devices exits in the EMF field we concentrate on cell biological findings and look for basic principles in the EF, MF and EMF action. As an outlook for future research topics, this review tries to link areas of EF, MF and EMF research to thermodynamics and quantum physics, approaches that will produce novel insights into cell biology.

  7. Biological effect of aerospace environment on alfalfa

    International Nuclear Information System (INIS)

    Zhang Yuexue; Liu Jielin; Han Weibo; Tang Fenglan; Hao Ruochao; Shang Chen; DuYouying; Li Jikai; Wang Changshan

    2009-01-01

    The biological effect of aerospace environment on two varieties of Medicago sativa L. was studied. In M 1 germination results showed that aerospace environment increased cell division and the number of micronucleus, changed germination rate, caused seedling aberrations. Cytogenetical and seedling aberration of Zhaodong showed more sensitivity than Longmu 803. Branches and fresh weight of Zhaodong had shown more serious damage than control and Longmu 803. (authors)

  8. Graphene oxide significantly inhibits cell growth at sublethal concentrations by causing extracellular iron deficiency.

    Science.gov (United States)

    Yu, Qilin; Zhang, Bing; Li, Jianrong; Du, Tingting; Yi, Xiao; Li, Mingchun; Chen, Wei; Alvarez, Pedro J J

    Graphene oxide (GO)-based materials are increasingly being used in medical materials and consumer products. However, their sublethal effects on biological systems are poorly understood. Here, we report that GO (at 10 to 160 mg/L) induced significant inhibitory effects on the growth of different unicellular organisms, including eukaryotes (i.e. Saccharomyces cerevisiae, Candida albicans, and Komagataella pastoris) and prokaryotes (Pseudomonas fluorescens). Growth inhibition could not be explained by commonly reported cytotoxicity mechanisms such as plasma membrane damage or oxidative stress. Based on transcriptomic analysis and measurement of extra- and intracellular iron concentrations, we show that the inhibitory effect of GO was mainly attributable to iron deficiency caused by binding to the O-functional groups of GO, which sequestered iron and disrupted iron-related physiological and metabolic processes. This inhibitory mechanism was corroborated with supplementary experiments, where adding bathophenanthroline disulfonate-an iron chelating agent-to the culture medium exerted similar inhibition, whereas removing surface O-functional groups of GO decreased iron sequestration and significantly alleviated the inhibitory effect. These findings highlight a potential indirect detrimental effect of nanomaterials (i.e. scavenging of critical nutrients), and encourage research on potential biomedical applications of GO-based materials to sequester iron and enhance treatment of iron-dependent diseases such as cancer and some pathogenic infections.

  9. Biologically effective dose (BED) for interstitial seed implants containing a mixture of radionuclides with different half-lives

    International Nuclear Information System (INIS)

    Chen Zhe; Nath, Ravinder

    2003-01-01

    Purpose: To develop a tool for evaluating interstitial seed implants that contain a mixture of radionuclides with different half-lives and to demonstrate its utility by examining the clinical implications of prescribing to an isodose surface for such an implant. Methods and Materials: A linear-quadratic model for continuous low dose rate irradiation was developed for permanent implants containing a mixture of radionuclides. Using a generalized equation for the biologically effective dose (BED), the effects of cell proliferation and sublethal damage repair were examined systematically for implants containing a mixture of radionuclides. A head-and-neck permanent seed implant that contained a mixture of 125 I and 103 Pd seeds was used to demonstrate the utility of the generalized BED. Results: An equation of BED for implants containing a mixture of radionuclides with different half-lives was obtained. In such an implant, the effective cell kill was shown to depend strongly on the relative dose contributions from each radionuclide type; dose delivered by radionuclides with shorter half-life always resulted in more cell kill for any given sublethal damage repair and cell proliferation rates. Application of the BED formula to an implant containing a mixture of 125 I and 103 Pd seeds demonstrates that the conventional dose prescription to an isodose surface is not unique for such an implant. When the prescription dose was based on existing clinical experience of using 125 I seeds alone, mixing 103 Pd seeds with 125 I seeds would increase the cell kill. On the other hand, if the prescription dose were based on existing clinical experience of using 103 Pd seeds alone, mixing 125 I seeds with 103 Pd seeds in the same implant would create radiobiologically 'cold' spots (i.e., an increase in cell survival) at locations where a major portion of the prescription dose is contributed by the 125 I seeds. For fast-growing tumors, these 'cold' spots can become significant

  10. The Biological Effects of Bilirubin Photoisomers

    Science.gov (United States)

    Jasprova, Jana; Dal Ben, Matteo; Vianello, Eleonora; Goncharova, Iryna; Urbanova, Marie; Vyroubalova, Karolina; Gazzin, Silvia; Tiribelli, Claudio; Sticha, Martin; Cerna, Marcela; Vitek, Libor

    2016-01-01

    Although phototherapy was introduced as early as 1950’s, the potential biological effects of bilirubin photoisomers (PI) generated during phototherapy remain unclear. The aim of our study was to isolate bilirubin PI in their pure forms and to assess their biological effects in vitro. The three major bilirubin PI (ZE- and EZ-bilirubin and Z-lumirubin) were prepared by photo-irradiation of unconjugated bilirubin. The individual photoproducts were chromatographically separated (TLC, HPLC), and their identities verified by mass spectrometry. The role of Z-lumirubin (the principle bilirubin PI) on the dissociation of bilirubin from albumin was tested by several methods: peroxidase, fluorescence quenching, and circular dichroism. The biological effects of major bilirubin PI (cell viability, expression of selected genes, cell cycle progression) were tested on the SH-SY5Y human neuroblastoma cell line. Lumirubin was found to have a binding site on human serum albumin, in the subdomain IB (or at a close distance to it); and thus, different from that of bilirubin. Its binding constant to albumin was much lower when compared with bilirubin, and lumirubin did not affect the level of unbound bilirubin (Bf). Compared to unconjugated bilirubin, bilirubin PI did not have any effect on either SH-SY5Y cell viability, the expression of genes involved in bilirubin metabolism or cell cycle progression, nor in modulation of the cell cycle phase. The principle bilirubin PI do not interfere with bilirubin albumin binding, and do not exert any toxic effect on human neuroblastoma cells. PMID:26829016

  11. Microwave radiation - Biological effects and exposure standards

    Energy Technology Data Exchange (ETDEWEB)

    Lindsay, I.R.

    1980-06-01

    The thermal and nonthermal effects of exposure to microwave radiation are discussed and current standards for microwave exposure are examined in light of the proposed use of microwave power transmission from solar power satellites. Effects considered include cataractogenesis at levels above 100 mW/sq cm, and possible reversible disturbances such as headaches, sleeplessness, irritability, fatigue, memory loss, cardiovascular changes and circadian rhythm disturbances at levels less than 10 mW/sq cm. It is pointed out that while the United States and western Europe have adopted exposure standards of 10 mW/sq cm, those adopted in other countries are up to three orders of magnitude more restrictive, as they are based on different principles applied in determining safe limits. Various aspects of the biological effects of microwave transmissions from space are considered in the areas of the protection of personnel working in the vicinity of the rectenna, interactions of the transmitted radiation with cardiac pacemakers, and effects on birds. It is concluded that thresholds for biological effects from short-term microwave radiation are well above the maximal power density of 1 mW/sq cm projected at or beyond the area of exclusion of a rectenna.

  12. Lethal and sublethal effects of naphthalene and 1,2-dimethylnaphthalene on naupliar and adult stages of the marine cyclopoid copepod Oithona davisae

    International Nuclear Information System (INIS)

    Saiz, Enric; Movilla, Juancho; Yebra, Lidia; Barata, Carlos; Calbet, Albert

    2009-01-01

    Short-term (24 h) exposure experiments have been conducted to determine the effects of two environmental relevant polycyclic aromatic hydrocarbons (PAHs), naphthalene (NAPH) and dimethylnaphthalene (C2-NAPH), on the naupliar and adult stages of the marine cyclopoid copepod Oithona davisae. To resemble more realistic conditions, those exposure experiments were conducted under the presence of food. The naupliar stages evidenced lower tolerance to PAH exposure regarding narcotic and lethal effects than adults. Copepod feeding activity showed to be very sensitive to the presence of the studied PAHs, detrimental effects occurring at toxic concentrations ca. 2-3 fold lower than for narcotic effects. In addition we report PAH-mediated changes in cell size and growth rate of the prey item, the heterotrophic dinoflagellate Oxyrrhis marina, that could indirectly affect copepod feeding and help explain hormesis-like responses in our feeding experiments. - The feeding activity of copepods is very sensitive to the direct and indirect (prey-viability mediated) effects of polycyclic aromatic hydrocarbons

  13. Lethal and sublethal effects of naphthalene and 1,2-dimethylnaphthalene on naupliar and adult stages of the marine cyclopoid copepod Oithona davisae

    Energy Technology Data Exchange (ETDEWEB)

    Saiz, Enric [Institut de Ciencies del Mar (ICM), CSIC, Ps. Maritim de la Barceloneta 37-49, E-08003 Barcelona, Catalunya (Spain)], E-mail: enric@icm.csic.es; Movilla, Juancho; Yebra, Lidia [Institut de Ciencies del Mar (ICM), CSIC, Ps. Maritim de la Barceloneta 37-49, E-08003 Barcelona, Catalunya (Spain); Barata, Carlos [Departament de Quimica Ambiental, Institut de Diagnostic Ambiental i Estudis de l' Aigua (IDAEA), CSIC, C/Jordi Girona 18-26, E-08034 Barcelona, Catalunya (Spain); Calbet, Albert [Institut de Ciencies del Mar (ICM), CSIC, Ps. Maritim de la Barceloneta 37-49, E-08003 Barcelona, Catalunya (Spain)

    2009-04-15

    Short-term (24 h) exposure experiments have been conducted to determine the effects of two environmental relevant polycyclic aromatic hydrocarbons (PAHs), naphthalene (NAPH) and dimethylnaphthalene (C2-NAPH), on the naupliar and adult stages of the marine cyclopoid copepod Oithona davisae. To resemble more realistic conditions, those exposure experiments were conducted under the presence of food. The naupliar stages evidenced lower tolerance to PAH exposure regarding narcotic and lethal effects than adults. Copepod feeding activity showed to be very sensitive to the presence of the studied PAHs, detrimental effects occurring at toxic concentrations ca. 2-3 fold lower than for narcotic effects. In addition we report PAH-mediated changes in cell size and growth rate of the prey item, the heterotrophic dinoflagellate Oxyrrhis marina, that could indirectly affect copepod feeding and help explain hormesis-like responses in our feeding experiments. - The feeding activity of copepods is very sensitive to the direct and indirect (prey-viability mediated) effects of polycyclic aromatic hydrocarbons.

  14. Effects of Short-Term Exposure to Sublethal Concentrations of Silver Nanoparticles on Histopathology and Electron Microscope Ultrastructure of Zebrafish (Danio Rerio Gills

    Directory of Open Access Journals (Sweden)

    Borhan Mansouri

    2015-11-01

    Full Text Available Background: The increasing use of nanomaterials and nanoproducts has increased the possibility of contamination of the environment, which may have adverse effects on different organisms. The aim of this study was to evaluate the effects of silver nanoparticles on histopathology and gill ultrastructure of zebrafish (Danio rerio under laboratory conditions. Methods: Zebrafish were exposed to four concentrations of silver nanoparticles (0.0015, 0.00375, 0.0075, and 0.015 mg/l for a period of 4 days. Gill ultrastructure and histopathological changes were studied using scanning electron microscope and haematoxylin - eosin staining. Results: Exposure to silver nanoparticles significantly (P < 0.001 increased the diameter of gill filaments and secondary lamellae, while silver nanoparticles significantly reduced the length of the secondary gills in zebrafish. Moreover, other changes such as vacuolization, dilated and clubbed tips, hyperplasia, edema, fusion, swelling of mucocytes, hypertrophy, and necrosis were observed. The effects of silver nanoparticles in zebrafish gills were dose dependent. Conclusion: Based on the adverse effects of AgNPs on zebrafish gills, silver nanoparticle solutions can be hazardous pollutants for the environment.

  15. Bystander effect: Biological endpoints and microarray analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhry, M. Ahmad [Department of Medical Laboratory and Radiation Sciences, College of Nursing and Health Sciences, University of Vermont, 302 Rowell Building, Burlington, VT 05405 (United States) and DNA Microarray Facility, University of Vermont, Burlington, VT 05405 (United States)]. E-mail: mchaudhr@uvm.edu

    2006-05-11

    In cell populations exposed to ionizing radiation, the biological effects occur in a much larger proportion of cells than are estimated to be traversed by radiation. It has been suggested that irradiated cells are capable of providing signals to the neighboring unirradiated cells resulting in damage to these cells. This phenomenon is termed the bystander effect. The bystander effect induces persistent, long-term, transmissible changes that result in delayed death and neoplastic transformation. Because the bystander effect is relevant to carcinogenesis, it could have significant implications for risk estimation for radiation exposure. The nature of the bystander effect signal and how it impacts the unirradiated cells remains to be elucidated. Examination of the changes in gene expression could provide clues to understanding the bystander effect and could define the signaling pathways involved in sustaining damage to these cells. The microarray technology serves as a tool to gain insight into the molecular pathways leading to bystander effect. Using medium from irradiated normal human diploid lung fibroblasts as a model system we examined gene expression alterations in bystander cells. The microarray data revealed that the radiation-induced gene expression profile in irradiated cells is different from unirradiated bystander cells suggesting that the pathways leading to biological effects in the bystander cells are different from the directly irradiated cells. The genes known to be responsive to ionizing radiation were observed in irradiated cells. Several genes were upregulated in cells receiving media from irradiated cells. Surprisingly no genes were found to be downregulated in these cells. A number of genes belonging to extracellular signaling, growth factors and several receptors were identified in bystander cells. Interestingly 15 genes involved in the cell communication processes were found to be upregulated. The induction of receptors and the cell

  16. Bystander effect: Biological endpoints and microarray analysis

    International Nuclear Information System (INIS)

    Chaudhry, M. Ahmad

    2006-01-01

    In cell populations exposed to ionizing radiation, the biological effects occur in a much larger proportion of cells than are estimated to be traversed by radiation. It has been suggested that irradiated cells are capable of providing signals to the neighboring unirradiated cells resulting in damage to these cells. This phenomenon is termed the bystander effect. The bystander effect induces persistent, long-term, transmissible changes that result in delayed death and neoplastic transformation. Because the bystander effect is relevant to carcinogenesis, it could have significant implications for risk estimation for radiation exposure. The nature of the bystander effect signal and how it impacts the unirradiated cells remains to be elucidated. Examination of the changes in gene expression could provide clues to understanding the bystander effect and could define the signaling pathways involved in sustaining damage to these cells. The microarray technology serves as a tool to gain insight into the molecular pathways leading to bystander effect. Using medium from irradiated normal human diploid lung fibroblasts as a model system we examined gene expression alterations in bystander cells. The microarray data revealed that the radiation-induced gene expression profile in irradiated cells is different from unirradiated bystander cells suggesting that the pathways leading to biological effects in the bystander cells are different from the directly irradiated cells. The genes known to be responsive to ionizing radiation were observed in irradiated cells. Several genes were upregulated in cells receiving media from irradiated cells. Surprisingly no genes were found to be downregulated in these cells. A number of genes belonging to extracellular signaling, growth factors and several receptors were identified in bystander cells. Interestingly 15 genes involved in the cell communication processes were found to be upregulated. The induction of receptors and the cell

  17. [Effect of different oxygen concentrations on biological properties of bone marrow hematopoietic stem cells of mice].

    Science.gov (United States)

    Ma, Yi-Ran; Ren, Si-Hua; He, Yu-Xin; Wang, Lin-Lin; Jin, Li; Hao, Yi-Wen

    2012-10-01

    This study purposed to investigate the effects of different oxygen concentrations and reactive oxygen species (ROS) on the biological characteristics of hematopoietic stem cells (HSC) and their possible mechanisms through simulating oxygen environment to which the peripheral blood HSC are subjected in peripheral blood HSCT. The proliferation ability, cell cycle, directed differentiation ability, ROS level and hematopoietic reconstitution ability of Lin(-)c-kit(+)Sca-1(+) BMHSC were detected by using in vitro amplification test, directional differentiation test, cell cycle analysis, ROS assay and transplantation of Lin(-)c-kit(+)Sca-1(+) HSC from sublethally irradiated mice respectively. The results showed that oxygen concentrations lower than normal oxygen concentration, especially in hypoxic oxygen environment, could reduce ROS generation and amplify more primitive CD34(+)AC133(+) HSC and active CD34(+) HSC, and maintain more stem cells in the G(0)/G(1) phase, which is more helpful to the growth of CFU-S and viability of mice. At the same time, BMHSC exposed to normal oxygen level or inconstant and greatly changed oxygen concentrations could produce a high level of ROS, and the above-mentioned features and functional indicators are relatively low. It is concluded that ROS levels of HSC in BMHSCT are closely related with the oxygen concentration surrounding the cells and its stability. Low oxygen concentration and antioxidant intervention are helpful to transplantation of BMHSC.

  18. Radiobiology: Biologic effects of ionizing radiations

    International Nuclear Information System (INIS)

    Held, K.D.

    1987-01-01

    The biologic effects after exposure to ionizing radiation, such as cell death or tissue injury, result from a chain of complex physical, chemical, metabolic, and histologic events. The time scale of these radiation actions spans many orders of magnitude. The physical absorption of ionizing radiation occurs in about 10 -18 s, while late carcinogenic and genetic effects are expressed years or even generations later. Collectively, these effects form the science of radiobiology. Many of the concepts discussed in this chapter have been developed through the study of effects generated in tissues by external radiation sources, but they apply generally and often specifically to internally distributed radiopharmaceuticals which form the central topic of this book

  19. Efectos subletales de la lambda-cialotrina sobre Eisenia fetida (Annelida, Oligochaeta, Lumbricidae Sublethal effects of lambda-cyhalothrin on Eisenia fetida (Annelida, Oligochaeta, Lumbricidae

    Directory of Open Access Journals (Sweden)

    Tamara Ricardo

    2010-07-01

    Full Text Available El uso intensivo de agroquímicos provoca efectos dañinos sobre la fauna no blanco. Dentro de la misma, los oligoquetos contribuyen a mantener la estructura y fertilidad del suelo. La lambda-cialotrina es uno de los insecticidas piretroides más utilizados en la Argentina, pero son escasos los datos existentes acerca de su toxicidad sobre oligoquetos. Los objetivos de este trabajo fueron evaluar mediante bioensayos de toxicidad crónica los efectos de lambda-cialotrina (producto comercial al 5% en Eisenia fetida sobre los parámetros de comportamiento, sobrevivencia, biomasa, reproducción y bioacumulación, así como la persistencia en suelo OECD de dicho tóxico. Los resultados muestran un comportamiento de huída intenso a partir de la concentración más baja, con un EC50 de 1,36 mg kg-1 (95% C.L. 0,24 - 2,80. No se observaron efectos en sobrevivencia y alimentación. La reproducción fue afectada significativamente (F= 11,94, PThe intensive use of agrochemicals has deleterious effects on non-target organisms. Among these organisms, earthworms are important because of their role in keeping the soil structure and fertility. Lambda-cyhalothrin is one of the most widely used pyrethroid insecticide in Argentina, but there are not enough studies of the effects of this pesticide on earthworms. The goals of this work were to perform chronic toxicity bioassays to determine the effects of commercial lambda-cyhalothrin (at 5% on Eisenia fetida. The parameters of behaviour, survival, biomass, reproduction, bioaccumulation and the degradation time of lambda-cyhalotrin in an OECD standard soil were also estimated. Results showed a hard avoidance behaviour in the lowest lambda-cyhalothrin concentration with an EC50 of 1.36 mg kg-1 (95% C.L 0.24-2.80. Eisenia fetida chronic test survival and feeding were not affected by lambda-cyhalothrin but negative effects on reproduction were significant (P<0.05. Cocoon production and fertility were reduced and

  20. The anti-inflammatory effect of melatonin in SH-SY5Y neuroblastoma cells exposed to sublethal dose of hydrogen peroxide.

    Science.gov (United States)

    Nopparat, Chutikorn; Chantadul, Varunya; Permpoonputtana, Kannika; Govitrapong, Piyarat

    2017-06-01

    Brain inflammaging is considered as one of the underlying factors of neurodegenerative diseases. The present study aimed to investigate the effects of melatonin, an endogenous indoleamine mainly synthesized by the pineal gland, on hydrogen peroxide (H 2 O 2 )-induced inflammaging state in SH-SY5Y cells. Our data showed that p21 Cip1 and p16 INK4a , cell cycle arrest markers, and the number of senescence-associated β-galactosidase (SA-βgal) staining increased significantly in H 2 O 2 -treated cells. Melatonin treatment could reverse this effect. Flow cytometry analysis showed a significantly higher percentage in the G0/G1 phase and a lower proportion in the S phase of H 2 O 2 treated cells. Cells pretreated with H 2 O 2 showed a dramatic decrease in the formation of Ki67 immunoactivity while the treatment with melatonin increased Ki67-positive cell. Both mRNA and protein expression levels of the pro-inflammatory cytokines, interleukin-1β (IL-1β), IL-6 and, tumor necrosis factor-α (TNF-α) which were increased after induction with H 2 O 2 , could be attenuated by melatonin. In addition, melatonin decreased the phospho-nuclear factor kappa B (pNF-κB) expression and prevented its nuclear translocation, as well as abrogated the reduction of nuclear factor erythroid 2-related factor 2 (Nrf2) in SH-SY5Y cells exposed to H 2 O 2 . The present data suggested the importance of melatonin on ameliorating inflammation in SH-SY5Y cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Xenon preconditioning: molecular mechanisms and biological effects

    Directory of Open Access Journals (Sweden)

    Liu Wenwu

    2013-01-01

    Full Text Available Abstract Xenon is one of noble gases and has been recognized as an anesthetic for more than 50 years. Xenon possesses many of the characteristics of an ideal anesthetic, but it is not widely applied in clinical practice mainly because of its high cost. In recent years, numerous studies have demonstrated that xenon as an anesthetic can exert neuroprotective and cardioprotective effects in different models. Moreover, xenon has been applied in the preconditioning, and the neuroprotective and cardioprotective effects of xenon preconditioning have been investigated in a lot of studies in which some mechanisms related to these protections are proposed. In this review, we summarized these mechanisms and the biological effects of xenon preconditioning.

  2. Relationship between sublethal injury and inactivation of yeast cells by the combination of sorbic acid and pulsed electric fields.

    Science.gov (United States)

    Somolinos, M; García, D; Condón, S; Mañas, P; Pagán, R

    2007-06-01

    The objective of this study was to investigate the occurrence of sublethal injury after the pulsed-electric-field (PEF) treatment of two yeasts, Dekkera bruxellensis and Saccharomyces cerevisiae, as well as the relation of sublethal injury to the inactivating effect of the combination of PEF and sorbic acid. PEF caused sublethal injury in both yeasts: more than 90% of surviving D. bruxellensis cells and 99% of surviving S. cerevisiae cells were sublethally injured after 50 pulses at 12 kV/cm in buffer at pHs of both 7.0 and 4.0. The proportion of sublethally injured cells reached a maximum after 50 pulses at 12.0 kV/cm (S. cerevisiae) or 16.5 kV/cm (D. bruxellensis), and it kept constant or progressively decreased at greater electric field strengths and with longer PEF treatments. Sublethally PEF-injured cells showed sensitivity to the presence of sorbic acid at a concentration of 2,000 ppm. A synergistic inactivating effect of the combination of PEF and sorbic acid was observed. Survivors of the PEF treatment were progressively inactivated in the presence of 2,000 ppm of sorbic acid at pH 3.8, with the combined treatments achieving more than log10 5 cycles of dead cells under the conditions investigated. This study has demonstrated the occurrence of sublethal injury after exposure to PEF, so yeast inactivation by PEF is not an all-or-nothing event. The combination of PEF and sorbic acid has proven to be an effective method to achieve a higher level of yeast inactivation. This work contributes to the knowledge of the mechanism of microbial inactivation by PEF, and it may be useful for improving food preservation by PEF technology.

  3. Kinetics of sublethal damage recovery in mouse lip mucosa comparing low and high-LET radiation

    International Nuclear Information System (INIS)

    Scalliet, P.; Landuyt, W.; Schueren, E. van der; Vynckier, S.; Wambersie, A.

    1989-01-01

    The effects of d(50)+Be neutrons on the lip mucosa in mice were investigated as a model of early effects. The biological endpoint eas the incidence of desquamation in the lower lip after selective irradiation of the snout of the animals. ED 50 (dose leading to desquamation in 50% of the animals) were calculated by probit analysis. Fractionated (two, four and ten fractions) and protracted (43.5, 11.5 and 0.88 Gy.h -1 ) irradiations have been carried out. Results were analysed using the mathematical method of Dale. An α/β of 39.6 Gy and a t 1/2 of recovery of sublethal damage of 47 min have been derived. These results have been compared to data previously obtained with cobalt-60 gamma rays. Using the same mathematical approach, and comparing similar fractionated and protracted experiments, an α/β of 7.4 Gy and a t 1/2 of recovery of 47 min have been calculated. There was no significant difference in the repair kinetics after irradiations with gamma rays or d(50)+Be neutrons. (orig.) [de

  4. Gulf of Mexico offshore operations monitoring experiment (GOOMEX), phase I : sublethal responses to contaminant exposure - introduction and overview

    International Nuclear Information System (INIS)

    Kennicutt, M.C.; Green, R.H.; Montagna, P.

    1996-01-01

    The Gulf of Mexico Offshore Operations Monitoring Experiment (GOOMEX) is a three-phase study to test and evaluate a range of biological, biochemical, and chemical methodologies to detect and assess chronic sublethal biological impacts in the vicinity of long-duration activities associated with oil and gas exploration and production. A chronic impact is defined as an effect on the biota caused by exposure to the long-term accumulation of chemicals in the environment. The basic program, comprising four field activities over a 2-yr period, was designed to detect nearfield impacts and contaminant gradients extending out from each site. Five test sites were evaluated and three selected as most appropriate for long-term study: MU-A85, MAI-686, and HI-A389. The sampling design included a radial pattern with stations at 30-50, 100, 200, 500, and 3000 m distance and employed a dose-response model to test the hypotheses that biological, chemical, and biochemical variations are due to platform-derived contaminants. Study components included contaminant (trace metals and hydrocarbons) analysis in sediments, pore waters, and biological tissues; assemblage analysis of benthic meiofauna, infauna, and epifauna, assessment of community health based on life history and reproduction studies; and the induction of detoxification responses. (author). 57 refs., 9 tabs., 5 figs

  5. Countermeasures for Space Radiation Induced Malignancies and Acute Biological Effects

    Science.gov (United States)

    Kennedy, Ann

    The hypothesis being evaluated in this research program is that control of radiation induced oxidative stress will reduce the risk of radiation induced adverse biological effects occurring as a result of exposure to the types of radiation encountered during space travel. As part of this grant work, we have evaluated the protective effects of several antioxidants and dietary supplements and observed that a mixture of antioxidants (AOX), containing L-selenomethionine, N-acetyl cysteine (NAC), ascorbic acid, vitamin E succinate, and alpha-lipoic acid, is highly effective at reducing space radiation induced oxidative stress in both in vivo and in vitro systems, space radiation induced cytotoxicity and malignant transformation in vitro [1-7]. In studies designed to determine whether the AOX formulation could affect radiation induced mortality [8], it was observed that the AOX dietary supplement increased the 30-day survival of ICR male mice following exposure to a potentially lethal dose (8 Gy) of X-rays when given prior to or after animal irradiation. Pretreatment of animals with antioxidants resulted in significantly higher total white blood cell and neutrophil counts in peripheral blood at 4 and 24 hours following exposure to doses of 1 Gy and 8 Gy. Antioxidant treatment also resulted in increased bone marrow cell counts following irradiation, and prevented peripheral lymphopenia following 1 Gy irradiation. Supplementation with antioxidants in irradiated animals resulted in several gene expression changes: the antioxidant treatment was associated with increased Bcl-2, and decreased Bax, caspase-9 and TGF-β1 mRNA expression in the bone marrow following irradiation. These results suggest that modulation of apoptosis may be mechanistically involved in hematopoietic system radioprotection by antioxidants. Maintenance of the antioxidant diet was associated with improved recovery of the bone marrow following sub-lethal or potentially lethal irradiation. Taken together

  6. Biological radiation effects of Radon in Drosophila

    International Nuclear Information System (INIS)

    Pimentel P, A.E.

    1995-01-01

    In order to contribute to the knowledge on the effects of radon and its decay products, the aim of this investigation is to study the biological effects of radon using Drosophila melanogaster throught the somatic mutation and recombination test (SMART) and the analysis of some adaptative factors exposing larvaes to controlled radon atmosphers, considering that this insect could be used as biological monitor. Using the somatic mutation test a mutagenic effect was observed proportional to radon concentration, into an interval of 1 ± 0.3 to 111 ± 7.4 KBq/m 3 equivalent to doses under 0.0106 Gy. The correlation analysis gives a linear (r=0.80) relationship with a positive slope of 0.2217. The same happens when gamma rays are used in the interval of 1 to 20 Gy, given a linear dose-dependent effect (r=0.878) is obtained; nevetheless the slop is smaller (m=0.003) than for radon. Analysing the results of adaptative factors of the nine exposed generations, it was found that probably radon exposition induced dominant lethals during gametogenesis or/and a selection of the more component gamets of the treated individuals in larval state. It was reflected in the significant decrease on fecundity of the generation exposed. Nevertheless the laying eggs had an increase in egg-to-adult viability and the develop velocity was higher than in control for 3 KBq/m 3 , this suggest that radon concentrations used were able to induce repair mechanisms. These data agree with the Hormesis hypothesis that says: low doses have positive effects on health. It was not possible to obtain a dose-effect relationship except with the develop velocity where it was found a dose-effect inverse proportion. In conclusion, Drosophila melanogaster could be a good system to obtain in vivo damaged induction concentration dependent of radon and its decay products, as well as to study the effects in an exposed population by the analysis of adaptative factors. (Author)

  7. Sublethal damages: their nature and repair

    Energy Technology Data Exchange (ETDEWEB)

    Saenko, A.S.; Synzynys, B.I.; Trofimova, S.F. (Nauchno-Issledovatel' skij Inst. Meditsinskoj Radiologii, Obninsk (USSR)); Gotlib, V.Ya.; Pelevina, I.I. (AN SSSR, Moscow. Inst. Khimicheskoj Fiziki)

    1983-05-12

    The molecular nature of sublethal damage (SLD) arising after ionizing irradiation of cultured mammalian cells was considered on the basis of data on DNA repair and cell recovery after SLD observed in lymphosarcoma cells as well as of literature data. The rate of SLD recovery and that of restoration of the cell's ability to initiate DNA synthesis were shown to be similar in new replicons. These data along with knowledge about the role of exchange type chromosomal aberrations in reproductive death permitted us to propose the hypothesis that conformational changes of chromatine - most probably, relaxation of condensed chromosomal material - are damage registered as SLD at the cellular level. Double-strand breaks and a slowly repaired part of DNA single-strand breaks are candidates for SLD.

  8. Food irradiation and its biological effects

    International Nuclear Information System (INIS)

    Shah, Alok; Nanjappa, C.; Chauhan, O.P.

    2014-01-01

    Irradiation of foods drew attention mostly in 1960s for disinfestation of food grains, spices and sprout inhibition in mainly potato and onion. γ-irradiation at 0.25 to 1 kGy dosage levels are usually used for irradiating grains, legumes, spices and sprout-prone vegetables. Irradiation of foods with in permissible dosage levels of 0.25 to 5 kGy is usually considered fairly safe from human consumption point of view not withstanding usual health concerns about its usage in foods. Irradiation of foods, in mostly solid or semi-solid form, at 5 kGy levels of γ-irradiation can achieve radicidation or, radiation equivalent of pasteurization and, if γ-irradiation is used at 10 kGy, it can achieve radappertization or, radiation equivalent of thermal commercial sterilization. However, the food industry uses γ-irradiation at 0.25 to 2 kGy only for mostly disinfestation of food grains/legumes, spices, sprout inhibition in potato and onion and, for surface sanitation of frozen fish, poultry and meat. Exposure to irradiation creates free radicals in foods that are capable of destroying some of the spoilage and pathogenic microflora but the same can also damage vitamins and enzymes besides creating some new harmful new chemical species, called unique radiolytic products (URPs), by combining with certain chemicals that a food may be laced with (like pesticides/fungicides). Exposure to high-energy electron beams are also known to create deleterious biological effects which may even lead to detection of trace amounts of radioactivity in the food. Some possible causes delineated for such harmful biological effects of irradiation include: irradiation induced vitamin deficiencies, the inactivity of enzymes in the foods, DNA damage and toxic radiolytic products in the foods. Irradiation, a non-thermal food preservation technique, has a role in salvaging enormous post harvest losses (25-30%) in developing economies to increase the per capita availability of foods. (author)

  9. Biological changes in experimental animals after irradiation with sublethal doses

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Dae Seong; Park, Yong Dae; Jin, Chang Hyun; Byun, Myung Woo; Jeong, Il Yun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2008-05-15

    The objective of the present study was to investigate general clinical aspects such as weekly body weight and blood changes, and weekly food intake in gamma-irradiated C57BL/6j male mice fed AIN-76A purified rodent diet for 14 weeks. The mice were whole-body irradiated with 0, 2, 4 and 6 Gy of gamma-rays (Gammacell 40 Exactor, {sup 137}Cs, MDS Nordion) at a dose rate of 1.8 {sub c}Gy per second. The mean body weight change of 6 Gy-irradiated mice significantly decreased when compared to that of the non-irradiated control mice. Moreover, high dose of radiation resulted in decreased levels of AST, ALT, but in increased levels of total cholersterol, triglyceride, HDL-C in mice.

  10. Biological effects of radon in Drosophila

    International Nuclear Information System (INIS)

    Pimentel P, A.E.; Tavera D, L.; Cruces M, M.P.; Arceo M, C.; Rosa D, M.E. de la

    1992-04-01

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  11. Dosimetry and biological effects of fast neutrons

    International Nuclear Information System (INIS)

    Zoetelief, J.

    1981-01-01

    This thesis contains studies on two types of cellular damage: cell reproductive death and chromosome aberrations induced by irradiation with X rays, gamma rays and fast neutrons of different energies. A prerequisite for the performance of radiobiological experiments is the determination of the absorbed dose with a sufficient degree of accuracy and precision. Basic concepts of energy deposition by ionizing radiation and practical aspects of neutron dosimetry for biomedical purposes are discussed. Information on the relative neutron sensitivity of GM counters and on the effective point of measurement of ionization chambers for dosimetry of neutron and photon beams under free-in-air conditions and inside phantoms which are used to simulate the biological objects is presented. Different methods for neutron dosimetry are compared and the experimental techniques used for the investigations of cell reproductive death and chromosome aberrations induced by ionizing radiation of different qualities are presented. Dose-effect relations for induction cell inactivation and chromsome aberrations in three cultured cell lines for different radiation qualities are presented. (Auth.)

  12. Ultraviolet radiation and its biological effects

    International Nuclear Information System (INIS)

    Rames, J.; Bencko, V.

    1993-01-01

    In connexion with contamination of the atmosphere with freons, the interest is increasing in geophysical and health aspects of 'ozone holes' - the seasonal incidence of increased intensity of UV radiation. Its biological effects depend on the intensity of the radiation, the exposure time and the wavelength. There is a wide range of various sorts of damage, local as well as general. In addition to skin pigmentation and symptoms produced by an elevated histamine blood level, also changes are found which may have more serious and permanent consequences: changes in the number and structure of Langerhans islets, changes of the peripheral capillary walls, dimerization of pyrimidine and thymine in DNA. These changes demonstrably contribute to the development of skin malignancies. After exposure of the eye, changes in pigmentation are found, and depending on the dose, possibly also development of conjunctivitis or retinal damage. Recently the interaction of UV radiation with arsenic was investigated. On the other side, therapeutic effects of UV radiation combined with chemotherapy are used in dermatology, eg., for inhibition of contact sensitization. (author) 42 refs

  13. Biological effects of tritium and its behavior in the body. Ratio of biological effects (RBE)

    International Nuclear Information System (INIS)

    Takeda, Hiroshi

    1997-01-01

    Biological effects of radiation is known to depend not only on the radiation energy absorbed in the cells and the tissues of an organism, but also on ionization density. RBE, a biological effects ratio is used to correct the difference in absorbed dose due to the kind of nuclide. Determination of RBE has been carried out with end points of various biological effects as indicators for characterization of tritium effects. Recently, the tritium RBE was estimated from the indicators such as carcinogenesis, gene abnormalities, teratogenesis and gonadal abnormalities. The RBE values for HTO and 3 H-thymidine were in the range of 0.7-4.5 and 0.9-5.9. The varieties in RBE values were thought to be caused by the differences in the species or cell lines used, those in end points such as cell death, induction of mutagenesis and those in the kind of radiation as the control as well as the dose rate. Thus, there were various factors mediating RBE. (M.N.)

  14. E. Biological effects of radiation on man

    International Nuclear Information System (INIS)

    1976-01-01

    This report firstly summarises information on the biological hazards of radiation and their relation to radiation dose, and hence estimates the biological risks associated with nuclear power production. Secondly, it describes the basis and present status of radiation protection standards in the nuclear power industry

  15. Subchronic exposure to sublethal dose of imidacloprid changes electrophysiological properties and expression pattern of nicotinic acetylcholine receptor subtypes in insect neurosecretory cells.

    Science.gov (United States)

    Benzidane, Yassine; Goven, Delphine; Abd-Ella, Aly Ahmed; Deshayes, Caroline; Lapied, Bruno; Raymond, Valérie

    2017-09-01

    Neonicotinoids are the most important class of insecticides used in agriculture over the last decade. They act as selective agonists of insect nicotinic acetylcholine receptors (nAChRs). The emergence of insect resistance to these insecticides is one of the major problems, which limit the use of neonicotinoids. The aim of our study is to better understand physiological changes appearing after subchronic exposure to sublethal doses of insecticide using complementary approaches that include toxicology, electrophysiology, molecular biology and calcium imaging. We used cockroach neurosecretory cells identified as dorsal unpaired median (DUM) neurons, known to express two α-bungarotoxin-insensitive (α-bgt-insensitive) nAChR subtypes, nAChR1 and nAChR2, which differ in their sensitivity to imidacloprid. Although nAChR1 is sensitive to imidacloprid, nAChR2 is insensitive to this insecticide. In this study, we demonstrate that subchronic exposure to sublethal dose of imidacloprid differentially changes physiological and molecular properties of nAChR1 and nAChR2. Our findings reported that this treatment decreased the sensitivity of nAChR1 to imidacloprid, reduced current density flowing through this nAChR subtype but did not affect its subunit composition (α3, α8 and β1). Subchronic exposure to sublethal dose of imidacloprid also affected nAChR2 functions. However, these effects were different from those reported on nAChR1. We observed changes in nAChR2 conformational state, which could be related to modification of the subunit composition (α1, α2 and β1). Finally, the subchronic exposure affecting both nAChR1 and nAChR2 seemed to be linked to the elevation of the steady-state resting intracellular calcium level. In conclusion, under subchronic exposure to sublethal dose of imidacloprid, cockroaches are capable of triggering adaptive mechanisms by reducing the participation of imidacloprid-sensitive nAChR1 and by optimizing functional properties of nAChR2, which is

  16. The late biological effects of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-06-15

    Full text: The principal objective of the symposium was to review the current status of understanding of the late biological effects of ionizing radiation from external and internal sources. A second objective was to critically evaluate information obtained from epidemiological studies of human population groups as well as from animal experimentation in order to provide a solid scientific basis upon which problems of current concern, such as radiation protection standards and risk-benefit analysis, could be deliberated. Eighty-one papers were presented in 10 sessions which covered epidemiological studies of late effects in human populations exposed to internal and/or external ionizing radiation; quantitative and qualitative data from animal experimentation of late effects; methodological problems and modern approaches; factors influencing susceptibility or expression of late radiation injury; comparative evaluation of late effects induced by radiation and other environmental pollutants, and problems of risk assessment. In addition, there were two evening sessions for free discussion of problems of interpreting animal data, and of the epidemiological studies of occupationally exposed populations. Reports on atomic bomb survivors showed that these epidemiological studies are providing dependable data, such as dose-related excess infant mortality. The reports also revealed the need for consensus in the method employed in the interpretation of data. That was also the case with studies on occupationally exposed populations at Hanford plant, where disparate results were presented on radiation-induced neoplasia among radiation workers. These data are, however, considered not so significant in relative terms when compared to risks involved in other industries. It was recommended that national registry systems for the dosimetry and medical records of radiation workers be established and co-ordinated internationally in order to facilitate reliable epidemiological

  17. Accounting for biological effectiveness in radiological protection

    International Nuclear Information System (INIS)

    Dennis, J.A.

    1989-01-01

    Relative biological effectiveness (RBE) presents a practical problem to radiological protection when attempts are made to ensure that the assessed risks from different types of radiation and different modes of exposure to radiation are commensurate with one another. Unfortunately, the theoretical understanding of RBE is still in the stage of competing explanations and hypotheses. Furthermore, the division of the concept of dose equivalent into a set of concepts for risk assessment and another set for measurement and control has introduced conflicting requirements of a practical nature that are difficult to resolve. Many of those working in radiobiology and radiation protection have perceived the need to increase the quality factors for photon and neutron radiations. It may be more reasonable to change the quality factors for neutrons than for other radiations. The advantages and disadvantages of different methods for accommodating such changes within the dose-equivalent concepts are to be examined. The method of accommodating such a change that has the least practical disadvantages is to increase the quality factors for all secondary particles produced in tissue by neutron radiations by a constant factor. The only disadvantage would be the perception that the quality factors for these secondary particles were not treated in a consistent fashion for all types of ionising radiation. (author)

  18. Biologically based multistage modeling of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    William Hazelton; Suresh Moolgavkar; E. Georg Luebeck

    2005-08-30

    This past year we have made substantial progress in modeling the contribution of homeostatic regulation to low-dose radiation effects and carcinogenesis. We have worked to refine and apply our multistage carcinogenesis models to explicitly incorporate cell cycle states, simple and complex damage, checkpoint delay, slow and fast repair, differentiation, and apoptosis to study the effects of low-dose ionizing radiation in mouse intestinal crypts, as well as in other tissues. We have one paper accepted for publication in ''Advances in Space Research'', and another manuscript in preparation describing this work. I also wrote a chapter describing our combined cell-cycle and multistage carcinogenesis model that will be published in a book on stochastic carcinogenesis models edited by Wei-Yuan Tan. In addition, we organized and held a workshop on ''Biologically Based Modeling of Human Health Effects of Low dose Ionizing Radiation'', July 28-29, 2005 at Fred Hutchinson Cancer Research Center in Seattle, Washington. We had over 20 participants, including Mary Helen Barcellos-Hoff as keynote speaker, talks by most of the low-dose modelers in the DOE low-dose program, experimentalists including Les Redpath (and Mary Helen), Noelle Metting from DOE, and Tony Brooks. It appears that homeostatic regulation may be central to understanding low-dose radiation phenomena. The primary effects of ionizing radiation (IR) are cell killing, delayed cell cycling, and induction of mutations. However, homeostatic regulation causes cells that are killed or damaged by IR to eventually be replaced. Cells with an initiating mutation may have a replacement advantage, leading to clonal expansion of these initiated cells. Thus we have focused particularly on modeling effects that disturb homeostatic regulation as early steps in the carcinogenic process. There are two primary considerations that support our focus on homeostatic regulation. First, a number of

  19. Biological applications of the Moessbauer effect

    International Nuclear Information System (INIS)

    Boulay, P.

    1968-12-01

    The applications of Moessbauer spectrometry in the fields of physics and chemistry have been increasing steadily since its discovery in 1958. Attempts have been made to find applications in biology. Two possibilities of investigation exist in this field: the study of mechanical or vibrational movements in certain animal organs, and the determination of the organic molecular structure in a biological context. An example is given of each of these possibilities. (author) [fr

  20. Sublethal effects of tritium on aquatic systems, effects of low-level chronic irradiation on embryonic development, effects of beryllium and lithium on aquatic systems, and teratogenic effects of low-level magnetic fields

    International Nuclear Information System (INIS)

    Strand, J.A.; Roesijadi, G.; Emery, R.M.

    1978-01-01

    It is conceivable, and possible, that with increasing applications of nuclear energy, greater quantities of potentially harmful radionuclides will be released to the environment. This may be particularly true for advanced reactor designs such as the fusion reactor where radionuclides, principally tritium, may be expected to escape from the plant both in gaseous and liquid effluents in quantities significantly greater than for present PWR or BWR designs. Foreseeing such contingencies, the research programs described herein are in response to the need to measure the potential radiation effects of tritium releases on individuals, and ultimately populations and biotic communities. As a first approach, our efforts are directed to determine effects of low-level chronic exposures on developing embryo and larval stages, clearly the most radiosensitive. The anticipated increase in the release of beryllium and lithium from mining, refining, and fabrication of materials used during construction of fusion reactors has also caused concern as to potential adverse effects on the environment. Accordingly, FY-78 fusion related research will include efforts to study the metabolism of each metal in the living organism, and to determine at what levels toxicity may be expected. Fusion related research will also include preliminary experiments on the effects of low-level magnetic fields. It is conceivable that magnetic fields of 70 to 450 gauss will be encountered by attendant personnel working in the transport and hot cell areas of fusion reactors. Also, those personnel assigned to the areas immediately surrounding the reactor may be exposed

  1. Biological effects of low-dose ionizing radiation exposure

    International Nuclear Information System (INIS)

    Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst

    2009-01-01

    The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

  2. Ecological aspects od electromagnetic irradiation effects of biological objects

    International Nuclear Information System (INIS)

    Volobuev, A.P.; Donnik, I.M.; Alekseenko, N.N.

    2005-01-01

    General description of electromagnetic field effects on biological objects depending on its frequency properties is stated in the paper. Basic principles of low frequency field effect (10 -1 -0 2 Hz) are detailed. General and specific regularities of biological objects response to a low frequency field on subcell, cell, and system levels were considered taking into account their functional state. (author)

  3. Studying of ion implantation effect on the biology in China

    International Nuclear Information System (INIS)

    Yu Zengliang

    1993-04-01

    Since low energy ion effect on the biology was observed, the ion implantation as a new mutagenic source has been widely used in improving crops and modifying microbes in China. The basic phenomenon of ion implantation effect on the biology and analytical results are reported, and the examples of its application and its further development are shown

  4. Response of sublethally irradiated monkeys to a replicating viral antigen

    International Nuclear Information System (INIS)

    Hilmas, D.E.; Spertzel, R.O.

    1975-01-01

    Temporal effects of exposure to sublethal, total-body x radiation (400 R) on responses to vaccination with the attenuated Venezuelan equine encephalomyelitis vaccine virus, TC-83, were examined in rhesus monkeys. Viremia, often with delayed onset, was prolonged even when irradiation preceded vaccination by 28 days. Virus titers were increased, particularly in groups irradiated 4 or 7 days before vaccination. Delay in appearance of hemagglutination-inhibition and serum-neutralizing antibody correlated closely with persistence of viremia in irradiated-vaccinated monkeys. The temporal course of antibody response was markedly affected by the interval between irradiation and injection of this replicating antigen. With longer intervals between irradiation and vaccination, the somewhat depressed antibody responses approached normal or surpassed those of nonirradiated monkeys. Vaccination 14 days after radiation exposure resulted in lethality to 8 of 12 monkeys, apparently as a result of secondary infection. The additional lymphopenic stress due to the effect of TC-83, superimposed on the severely depressed hematopoietic competence at 14 days, undoubtedly contributed to this increased susceptibility to latent infection

  5. Immunomodulatory Effects of Macrolide Antibiotics - Part 1 : Biological Mechanisms

    NARCIS (Netherlands)

    Altenburg, J.; de Graaff, C. S.; van der Werf, T. S.; Boersma, W. G.

    2011-01-01

    Macrolide antibiotics are well known for their antibacterial and anti-inflammatory properties. This article provides an overview of the biological mechanisms through which macrolides exert this 'double effect'. Their antibacterial effect consists of the inhibition of bacterial protein synthesis,

  6. Biological effects of accelerated boron, carbon, and neon ions

    International Nuclear Information System (INIS)

    Grigoryev, Yu.G.; Ryzhov, N.I.; Popov, V.I.

    1975-01-01

    The biological effects of accelerated boron, carbon, and neon ions on various biological materials were determined. The accelerated ions included 10 B, 11 B, 12 C, 20 Ne, 22 Ne, and 40 Ar. Gamma radiation and x radiation were used as references in the experiments. Among the biological materials used were mammalian cells and tissues, yeasts, unicellular algae (chlorella), and hydrogen bacteria. The results of the investigation are given and the biophysical aspects of the problem are discussed

  7. Protein synthesis and sublethal damage repair in synchronized CHO cells

    International Nuclear Information System (INIS)

    Yezzi, M.J.; Tobias, C.A.; Blakely, E.A.

    1984-01-01

    The authors have previously reported that the split dose survival response to x-rays of asynchronous CHO-TSH1 cells is reduced if the cells are held at 40 0 C,a temperature that inhibits protein synthesis, for 2 hours before the first dose and during a 2-hour interval between doses. In conjunction with the survival experiments on asynchronous cells, the authors also examined the DNA rejoining ability in split dose studies with and without inhibition of protein synthesis. The results of these experiments suggest that inhibition of protein synthesis affects a pool of proteins that are necessary for the correct expression of the DNA, although they do not appear to be involved in rejoining DNA breaks. They have extended this work to the study of cells synchronized in G1 phase (2 hour post-mitosis) and S phase (10 hour post-mitosis). Autoradiographic analyses, using 3H-TdR pulse labeling, demonstrated that a delay in the progression of each synchronized cell population occurs after inhibition of protein synthesis. Data are reported on the effects of inhibition of protein synthesis on the ability of G1 and S phase cells to repair sublethal damage

  8. Generation of Composite Dose and Biological Effective Dose (BED) Over Multiple Treatment Modalities and Multistage Planning Using Deformable Image Registration

    International Nuclear Information System (INIS)

    Zhang, Geoffrey; Huang, T-C; Feygelman, Vladimir; Stevens, Craig; Forster, Kenneth

    2010-01-01

    Currently there are no commercially available tools to generate composite plans across different treatment modalities and/or different planning image sets. Without a composite plan, it may be difficult to perform a meaningful dosimetric evaluation of the overall treatment course. In this paper, we introduce a method to generate composite biological effective dose (BED) plans over multiple radiotherapy treatment modalities and/or multistage plans, using deformable image registration. Two cases were used to demonstrate the method. Case I was prostate cancer treated with intensity-modulated radiation therapy (IMRT) and a permanent seed implant. Case II involved lung cancer treated with two treatment plans generated on two separate computed tomography image sets. Thin-plate spline or optical flow methods were used as appropriate to generate deformation matrices. The deformation matrices were then applied to the dose matrices and the resulting physical doses were converted to BED and added to yield the composite plan. Cell proliferation and sublethal repair were considered in the BED calculations. The difference in BED between normal tissues and tumor volumes was accounted for by using different BED models, α/β values, and cell potential doubling times. The method to generate composite BED plans presented in this paper provides information not available with the traditional simple dose summation or physical dose summation. With the understanding of limitations and uncertainties of the algorithms involved, it may be valuable for the overall treatment plan evaluation.

  9. Effectiveness of a biological control agent Palexorista gilvoides in ...

    African Journals Online (AJOL)

    ACSS

    Effectiveness of a biological control agent Palexorista gilvoides in controlling Gonometa podorcarpi in conifer ... gilvoides as a potential biological control agent for G. podocarpi. Field and laboratory studies further established that P. .... version for windows (SPSS, 2002). Results. Gonometa podocarpi was present in.

  10. The radiobiology of laser-driven particle beams: focus on sub-lethal responses of normal human cells

    International Nuclear Information System (INIS)

    Manti, L.; Perozziello, F.M.; Romagnani, L.; Borghesi, M.; Doria, D.; Candiano, G.; Cirrone, G.A.P.; Leanza, R.; Romano, F.; Scuderi, V.; Tramontana, A.; Chaudhary, P.; Gwynne, D.; Prise, K. M.

    2017-01-01

    Accelerated proton beams have become increasingly common for treating cancer. The need for cost and size reduction of particle accelerating machines has led to the pioneering investigation of optical ion acceleration techniques based on laser-plasma interactions as a possible alternative. Laser-matter interaction can produce extremely pulsed particle bursts of ultra-high dose rates (≥ 10 9 Gy/s), largely exceeding those currently used in conventional proton therapy. Since biological effects of ionizing radiation are strongly affected by the spatio-temporal distribution of DNA-damaging events, the unprecedented physical features of such beams may modify cellular and tissue radiosensitivity to unexplored extents. Hence, clinical applications of laser-generated particles need thorough assessment of their radiobiological effectiveness. To date, the majority of studies have either used rodent cell lines or have focussed on cancer cell killing being local tumour control the main objective of radiotherapy. Conversely, very little data exist on sub-lethal cellular effects, of relevance to normal tissue integrity and secondary cancers, such as premature cellular senescence. Here, we discuss ultra-high dose rate radiobiology and present preliminary data obtained in normal human cells following irradiation by laser-accelerated protons at the LULI PICO2000 facility at Laser Lab Europe, France.

  11. Topical Day on Biological Effects of Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Baatout, S.; Jacquet, P.

    1997-05-15

    The topical day has been focussed on the potential effects of ionizing radiation on human health. A general overview on molecular and biophysical aspects of radiation, its effects on cells and organisms, and the contribution of radiobiology to radiation protection and risk assessment is given. The genetic effects of radiation and its effects on the developing organism, the effects of radiation on the cell cycle and the mechanisms of radiation induced apoptosis were also discussed.

  12. Topical Day on Biological Effects of Radiation

    International Nuclear Information System (INIS)

    Baatout, S.; Jacquet, P.

    1997-01-01

    The topical day has been focussed on the potential effects of ionizing radiation on human health. A general overview on molecular and biophysical aspects of radiation, its effects on cells and organisms, and the contribution of radiobiology to radiation protection and risk assessment is given. The genetic effects of radiation and its effects on the developing organism, the effects of radiation on the cell cycle and the mechanisms of radiation induced apoptosis were also discussed

  13. Is Reintroduction Biology an Effective Applied Science?

    Science.gov (United States)

    Taylor, Gemma; Canessa, Stefano; Clarke, Rohan H; Ingwersen, Dean; Armstrong, Doug P; Seddon, Philip J; Ewen, John G

    2017-11-01

    Reintroduction biology is a field of scientific research that aims to inform translocations of endangered species. We review two decades of published literature to evaluate whether reintroduction science is evolving in its decision-support role, as called for by advocates of evidence-based conservation. Reintroduction research increasingly addresses a priori hypotheses, but remains largely focused on short-term population establishment. Similarly, studies that directly assist decisions by explicitly comparing alternative management actions remain a minority. A small set of case studies demonstrate full integration of research in the reintroduction decision process. We encourage the use of tools that embed research in decision-making, particularly the explicit consideration of multiple management alternatives because this is the crux of any management decisions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Effects of antibiotic decontamination of the GI tract and pretreatment with sublethal doses of endotoxins on survival after whole-liver irradiation and 2/3 partial hepatectomy (PH)

    International Nuclear Information System (INIS)

    Geraci, J.P.; Jackson, K.L.; Mariano, M.S.; Leitch, J.M.

    1984-01-01

    Thirty-two rats were preconditioned by I.P. injection of sublethal doses of E. Coli endotoxin two weeks before irradiation. Thirty-two other animals were sham injected with endotoxin free water. One week before irradiation half of the endotoxin treated animals and half the sham-injected animals received non-absorbable antibiotics in their drinking water to decontaminate the intestinal tract. All 64 animals were exposed to 30 Gy whole-liver gamma-irradiation after surgically exposing the liver and moving the G.I. tract, spleen, and stomach out of the radiation field. Immediately after irradiation a 2/3 PH was performed. The animals were checked daily for 100 days postirradiation. Median survival times for sham-treated, decontaminated, endotoxin-treated, and endotoxin-treated + decontaminated animals were, respectively, 16, 26, 38, and 85 days. All animals died within 100 days except in the group receiving both endotoxin and antibiotic treatments. One third of these animals are still alive 100 days after irradiation. The significance of these results with respect to mechanisms of hepatic radiation injury are discussed

  15. Solar ultraviolet radiation effects on biological systems

    International Nuclear Information System (INIS)

    Diffey, B.L.

    1991-01-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK)

  16. Solar ultraviolet radiation effects on biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Diffey, B.L. (Dryburn Hospital, Durham (UK). Regional Medical Physics Dept.)

    1991-03-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK).

  17. Effects of marine reserves on the reproductive biology and ...

    African Journals Online (AJOL)

    Effects of marine reserves on the reproductive biology and recruitment rates of commonly and rarely exploited limpets. ... For recruitment, we hypothesised that if recruits are attracted to adults or survive better ... AJOL African Journals Online.

  18. Influence of the 192Ir source decay on biological effect

    International Nuclear Information System (INIS)

    Wang Shunbao; Feng Ningyuan; Niu Wenzhe; Yang Yuhui; Guo Lei

    1994-01-01

    Biological effect of the 192 Ir high activity source on LA 795 tumor of mice and HCT-8 cells have been investigated when decay of the source power from 340.4 GBq to 81.4 GBq no marked difference was found between the two cell survival curves of HCT-8 cells and both of them compared with that of the X-ray irradiation the value of relative biological effect (0.1 survival) was 0.43. On the experiment of tumor LA 795 of mice, when the source power was 293.3 GBq and 96.2 GBq, no different biological effect can be seen between the two series of figures. The relative biological effect was 0.55-0.60 (tumor growth delay) comparing with those of X-ray irradiation

  19. Iron diminishes the in vitro biological effect of vanadium.

    Science.gov (United States)

    Mechanistic pathways underlying inflammatory injury following exposures to vanadium-containing compounds are not defined. We tested the postulate that the in vitro biological effect of vanadium results from its impact on iron homeostasis. Human bronchial epithelial (HBE) cells ex...

  20. Effect of Biological and Chemical Ripening Agents on the Nutritional ...

    African Journals Online (AJOL)

    Effect of Biological and Chemical Ripening Agents on the Nutritional and Metal Composition of Banana ( Musa spp ) ... Journal Home > Vol 18, No 2 (2014) > ... curcas leaf were used and compared with a control with no ripening agent.

  1. Distinguishing between "function" and "effect" in genome biology.

    Science.gov (United States)

    Doolittle, W Ford; Brunet, Tyler D P; Linquist, Stefan; Gregory, T Ryan

    2014-05-09

    Much confusion in genome biology results from conflation of possible meanings of the word "function." We suggest that, in this connection, attention should be paid to evolutionary biologists and philosophers who have previously dealt with this problem. We need only decide that although all genomic structures have effects, only some of them should be said to have functions. Although it will very often be difficult or impossible to establish function (strictly defined), it should not automatically be assumed. We enjoin genomicists in particular to pay greater attention to parsing biological effects. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  2. Biological effects induced by low amounts of nuclear fission products

    International Nuclear Information System (INIS)

    Vasilenko, I.Ya.; Shishkin, V.F.; Khudyakova, N.V.

    1991-01-01

    The review deals with the problem of biological hazard of low radiation doses for animals and human beings taking into the danger of internal and external irradiation by nuclear fission products under conditions of enhancing anthropogenic radiation contamination of biosphere. An attention is paid to the estimation of life span carcinogenesis, genetic and delayed effects. A conclusion is made on a necessity of multiaspect investigation of biological importance of low radiation doses taking into account modifying effects of other environmental factors

  3. Interactions between Entomopathogenic Fungus, Metarhizium Anisopliae and Sublethal Doses of Spinosad for Control of House Fly, Musca Domestica

    Directory of Open Access Journals (Sweden)

    M Sharififard

    2011-06-01

    Full Text Available Background: Metarhizium anisopliae strain IRAN 437C is one of the most virulent fungal isolates against house fly, Musca domestica. The objective of this study was to determine the interaction of this isolate with sublethal doses of spino­sad against housefly.Methods: In adult bioassay, conidia of entomopathogenic fungus were applied as inoculated bait at 105 and 107 spore per gram and spinosad at 0.5, 1 and 1.5 µg (A.I. per gram bait. In larval bioassay, conidia were applied as combina­tion of spore with larval bedding at 106 and 108 spore per gram and spinosad at sublethals of 0.002, 0.004 and 0.006 µg (AI per gram medium. Results: Adult mortality was 48% and 72% for fungus alone but ranged from 66–87% and 89–95% in combination treat­ments of 105 and 107 spore/g with sublethal doses of spinosad respectively. The interaction between 105 spore/g with sublethals exhibited synergistic effect, but in combination of 107 spore in spite of higher mortality, the interac­tion was additive. There was significant difference in LT50 among various treatments. LT50 values in all combination treat­ments were smaller than LT50 values in alone ones. Larval mortality was 36% and 69% for fungus alone but ranged from 58%–78% and 81%–100% in combination treatments of 106 and 108 spore/g medium with sublethals of spino­sad respectively. The interaction was synergistic in all combination treatments of larvae.Conclusion: The interaction between M. anispliae and spinosad indicated a synergetic effect that increased the house fly mortality as well as reduced the lethal time.

  4. Current research in Canada on biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Marko, A.M.

    1980-05-01

    A survey of current research in Canada on the biological effects of ionizing radiation has been compiled. The list of projects has been classified according to structure (organizational state of the test system) as well as according to the type of effects. Using several assumptions, ballpark estimates of expenditures on these activities have been made. Agencies funding these research activities have been tabulated and the break-down of research in government laboratories and in academic institutions has been designated. Wherever possible, comparisons have been made outlining differences or similarities that exist between the United States and Canada concerning biological radiation research. It has been concluded that relevant research in this area in Canada is inadequate. Wherever possible, strengths and weaknesses in radiation biology programs have been indicated. The most promising course for Canada to follow is to support adequately fundamental studies of the biological effects of radiation. (auth)

  5. Biological effects of water reservoir radioactive contamination

    International Nuclear Information System (INIS)

    Mashneva, N.I.

    1983-01-01

    Radiation damage to fresh water fishes at early stages of ontogenesis is revealed only during the spawn incubation in a solution with 10 -5 to 10 -3 Cu/l radioactivity and at relatively high dosages exceeding 500-1000 rad. Damaging effect of a fission product mixture of 9, 30 and 100 day age as well as of several separate radionuclides on embryogenesis of freshwater fishes depends mainly on fish species, concentration, toxicity, chemical form of radionuclides in the residence medium, on peculiarities of metabolism between the aqueous medium and an organism, stage of the embryo development by the moment of radiation effect and duration of this effect

  6. Biological effects and hazards of radiation exposure

    International Nuclear Information System (INIS)

    Boas, J.F.; Solomon, S.B.

    1990-01-01

    Radiation induced carcinogenesis and mutagenesis form the main risk to health from exposure to low levels of radiation. This risk effects can be at least qualitatively understood by considering the effects of radiation on cell DNA. Whilst exposure to high levels of radiation results in a number of identifiable effects, exposure to low levels of radiation may result in effects which only manifest themselves after many years. Risk estimates for low levels of radiation have been derived on the basis of a number of assumptions. In the case of uranium mine workers a major hazard arises from the inhalation of radon daughters. Whilst the correlation between radon daughter exposure and lung cancer incidence is well established, the numerical value of the risk factor is the subject of controversy. ICRP 50 gives a value of 10 cases per 10 6 person-years at risk per WLM (range 5-15 x 10 -6 PYR -1 WLM -1 ). The effect of smoking on lung cancer incidence rates amongst miners is also controversial. Nevertheless, smoking by miners should be discouraged

  7. On the mechanism of the biological effect of ionizing radiation

    International Nuclear Information System (INIS)

    Margulis, M.A.; Margulis, I.M.

    2005-01-01

    The mechanisms of the biological effects of ionizing radiation (IR) and ultrasound (US) were considered. The current views on the nature of toxicity of IR, which is usually assigned to the formation of radicals in living tissues and to the straight-line collision of an ionizing particle with the DNA molecule, were analyzed. It was established that the amount of radicals formed in biological tissues in conditions of ultrasonically induced cavitation can be as large as that for IR; however, the biological effect of US is much softer as compared to IR. It was shown that the contribution of the indirect mechanism to the total biological effect of IR can be estimated by comparing US and IR in their chemical action; the contribution of the indirect mechanism to the biological effect of IR was found to be negligibly small. An alternative mechanism was proposed to explain the biological effect of IR. In accordance with the proposed model, IR with a high linear energy transfer (LET) value breaks through cell walls and biological membranes and causes damage to them, such that the cell can lose its regenerative capacity. Moreover, high-energy heavy ionizing particles perforate cytoplasm to form channels. Ionizing radiation with a low LET value (γ- and X-rays) causes multiple damages to biological membranes. Ionizing particles can also cause damages to membranes of mitochondria thus affecting the mechanism of cellular respiration, which will cause neoplastic diseases. The straight-line collision of an ionizing particle with a DNA molecule was found to be 5-7 orders of magnitude less probable as compared to the collision with a wall or membrane. It was shown that multiple perforations of cell walls and damages to membranes are characteristic only of ionizing particles, which have sufficiently long tracks, and do not occur upon exposure to ultrasonic waves, microwaves, UV radiation, and magnetic fields [ru

  8. Biological Effects of Individual Alpha Particles

    International Nuclear Information System (INIS)

    L. A. Braby; R. R. Ford

    2002-01-01

    In order to provide quantitative data on the mechanisms of intercellular communication leading to bystander effects in irradiated cell populations, a positive ion microbeam irradiation system was set up at Texas A and M University and the rate at which photobleached and active fluorescent molecules are exchanged between irradiated and unirradiated cells was studied. AG1522 human fibroblast cells were chosen as one of the lines in this study because they had been shown to be proficient at bystander effects, and because they exhibited scrape loading response and lindane inhibition of effects which suggest that gap junction communication was involved. Surprisingly, detailed measurements of recovery from photobleaching suggested that gap junction communication did not occur in these cells. More detailed studies with gap junction inhibitors and with immunohistochemistry assays for gap junctions seem to confirm that these cells do not communicate in this way. A cell line which does communicate by gap junctions, Clone 9, shows no change in communication rates before and after irradiation. Other techniques, such as assessment of nuclear cross section were developed to determine if bystander effects alter cell progression through the cell cycle and the growth of individual cells

  9. Biological effects of fruit and vegetables

    DEFF Research Database (Denmark)

    Dragsted, L. O.; Krath, B.; Ravn-Haren, Gitte

    2006-01-01

    A strong and persistent effect of plant-derived foods on the prevention of lifestyle diseases has emerged from observational studies. Several groups of constituents in plants have been identified as potentially health promoting in animal studies, including cholesterol-lowering factors, antioxidan...

  10. Sublethal toxicity and biotransformation of pyrene in Lumbriculus variegatus (Oligochaeta)

    International Nuclear Information System (INIS)

    Maeenpaeae, K.; Leppaenen, M.T.; Kukkonen, J.V.K.

    2009-01-01

    The aim of this work was to study the toxicity and biotransformation of polyaromatic hydrocarbon (PAH) pyrene in the oligochaete aquatic worm, Lumbriculus variegatus. PAHs are ubiquitous environmental pollutants that pose a hazard to aquatic organisms, and metabolizing capability is poorly known in the case of many invertebrate species. To study the toxicity and biotransformation of pyrene, the worm was exposed for 15 days to various concentrations of water-borne pyrene. The dorsal blood vessel pulse rate was used as a sublethal endpoint. Pyrene biotransformation by L. variegatus was studied and the critical body residues (CBR) were estimated for pyrene toxicity. The toxicokinetics of pyrene uptake was evaluated. A combination of radiolabeled ( 14 C) and nonlabeled pyrene was used in the exposures, and liquid scintillation counting (LSC) and high-pressure liquid chromatography were employed in both water and tissue residue analyses. The results showed that L. variegatus was moderately able to metabolize pyrene to 1-hydroxypyrene (1-HP), thus demonstrating that the phase-I-like oxidizing enzyme system metabolizes pyrene in L. variegatus. The amount of the 1-HP was 1-2% of the amount of pyrene in the worm tissues. The exposure to pyrene reduced the blood vessel pulse rate significantly (p < 0.05), showing that pyrene had a narcotic effect. The estimated CBRs remained constant during the exposure time, varying from 0.120 to 0.174 mmol pyrene/kg worm wet weight. The bioconcentration factors (BCF) decreased as exposure concentration increased. It was suggested that the increased toxicity of pyrene accounted for the decrease in BCFs by lowering the activity of the organism

  11. Biological effects of fruit and vegetables.

    Science.gov (United States)

    Dragsted, Lars O; Krath, Britta; Ravn-Haren, Gitte; Vogel, Ulla B; Vinggaard, Anne Marie; Bo Jensen, Per; Loft, Steffen; Rasmussen, Salka E; Sandstrom, The late BrittMarie; Pedersen, Anette

    2006-02-01

    A strong and persistent effect of plant-derived foods on the prevention of lifestyle diseases has emerged from observational studies. Several groups of constituents in plants have been identified as potentially health promoting in animal studies, including cholesterol-lowering factors, antioxidants, enzyme inducers, apoptosis inducers etc. In human intervention studies the dose levels achieved tend to be lower than the levels found to be effective in animals and sampling from target organs is often not possible. A controlled dietary human intervention study was performed with forty-three volunteers, providing 600 g fruit and vegetables/d or in the controls a carbohydrate-rich drink to balance energy intake. Surrogate markers of oxidative damage to DNA, protein and lipids, enzymic defence and lipid metabolism were determined in blood and urine. It was found that a high intake of fruit and vegetables tends to increase the stability of lipids towards oxidative damage. Markers of oxidative enzymes indicate a steady increase in glutathione peroxidase (GPX1) activity in erythrocytes during intervention with fruit and vegetables but there is no effect on GPX1 transcription levels in leucocytes. No change occurs in glutathione-conjugating or -reducing enzyme activities in erythrocytes or plasma, and there are no effects on the transcription of genes involved in phase 2 enzyme induction or DNA repair in leucocytes. Fruit and vegetable intake decreases the level of total cholesterol and LDL-cholesterol, but does not affect sex hormones. In conclusion, it has been shown that total cholesterol and LDL-cholesterol, markers of peripheral lipid oxidation, and erythrocyte GPX1 activity are affected by high intakes of fruit and vegetables. This finding provides support for a protective role of dietary fruit and vegetables against CVD.

  12. Biological Effects of Neutron and Proton Irradiations. Vol. II. Proceedings of the Symposium on Biological Effects of Neutron Irradiations

    International Nuclear Information System (INIS)

    1964-01-01

    During recent years the interest in biological effects caused by neutrons has been increasing steadily as a result of the rapid development of neutron technology and the great number of neutron sources being used. Neutrons, because of their specific physical characteristics and biological effects, form a special type of radiation hazard but, at the same time, are a prospective tool for applied radiobiology. This Symposium, held in Brookhaven at the invitation of the United States Government from 7-11 October 1963, provided an opportunity for scientists to discuss the experimental information at present available on the biological action of neutrons and to evaluate future possibilities. It was a sequel to the Symposium on Neutron Detection, Dosimetry and Standardization, which was organized by the International Atomic Energy Agency in December 1962 at Harwell. The Symposium was attended by 128 participants from 17 countries and 6 international organizations. Fifty-four papers were presented. The following subjects were discussed in various sessions: (1) Dosimetry. Estimation of absorbed dose of neutrons in biological material. (2) Biological effects of high-energy protons. (3) Cellular and genetic effects. (4) Pathology of neutron irradiation, including acute and chronic radiation syndromes (mortality, anatomical and histological changes, biochemical and metabolic disturbances) and delayed consequences. (5) Relative biological effectiveness of neutrons evaluated by different biological tests. A Panel on Biophysical Considerations in Neutron Experimentation, with special emphasis on informal discussions, was organized during the Symposium. The views of the Panel are recorded in Volume II of the Proceedings. Many reports were presented on the important subject of the relative effectiveness of the biological action of neutrons, as well as on the general pathology of neutron irradiation and the cellular and genetic effects related to it. Three survey papers considered

  13. The RBE of tritium-beta exposure for the induction of the adaptive response and apoptosis; cellular defense mechanisms against the biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Boreham, D.R.; Bahen, M.E.; Dolling, J-A.

    1997-01-01

    Adaption to radiation is one of a few biological responses that has been demonstrated to occur in mammalian cells exposed to doses of ionizing radiation in the occupational exposure range. The adaptive response has been well characterized in the yeast Saccharomyces cerevisiae, although the doses required to induce the response are higher than in mammalian cells. When yeast cells are primed with sublethal doses of gamma-radiation, they subsequently undergo an adaptive response and develop resistance to radiation, heat the chemical mutagens in a time and dose dependent manner. We have used this model system to assess the relative ability of tritium-beta radiation to induce the adaptive response the examined tritium-induced radiation resistance, thermal tolerance and suppression of mutation. The results show that sublethal priming doses of tritium caused yeast cells to develop resistance to radiation, heat, and a chemical mutagen MNNG. The magnitude and kinetics of the response, per unit dose, were the same for tritium and gamma-radiation. Therefore, the relative biological effectiveness (RBE) of tritium induction of the adaptive response was about 1.0. Apoptosis is a genetically programmed cell death or cell suicide. Cells damaged by radiation can be selectively removed from the population by apoptosis and therefore eliminated as a potential cancer risk to the organism. Since we have previously shown that apoptosis is a sensitive indicator of radiation damage in human lymphocytes exposed to low doses, we have used this endpoint to investigate the potency of tritium-beta radiation. Initially, tritium was compared to X-rays for relative effectiveness at inducing apoptosis. The results showed the lymphocytes irradiated in vitro with X-rays or tritium had similar levels of apoptosis per unit dose. Therefore the relative biology effectiveness of tritium for induction of apoptosis in human lymphocytes was also about 1. In the work presented here, we have demonstrated that

  14. Nanosilver – Harmful effects of biological activity

    Directory of Open Access Journals (Sweden)

    Anna Maria Świdwińska-Gajewska

    2014-12-01

    Full Text Available Nanosilver, also identified as colloidal silver, has been known and used for ages to combat diseases or prolong food freshness. It usually occurs in the form of a suspension consisting of particles of size < 100 nm. Due to its specific properties, silver nanoparticles are used in many technologies to produce medical devices, textiles, conductive materials or photovoltaic cells. The growing popularity of nanosilver applications increases the number of people occupationally exposed to this substance. Potential exposure routes for silver nanoparticles are through dermal, oral and inhalation pathways. Silver nanoparticles may be absorbed through the lungs, intestine, and through the skin into circulation and thus may reach such organs as the liver, kidney, spleen, brain, heart and testes. Nanosilver may cause mild eyes and skin irritations. It can also act as a mild skin allergen. Inhalation of silver nanoparticles mainly affects the lungs and liver. It has been demonstrated that silver nanoparticles may be genotoxic to mammalian cells. There are some alarming reports on the adverse effects of silver nanoparticles on reproduction of experimental animals. Exposure to silver nanoparticles may exert a neurotoxic effect and affect cognitive functions, causing the impairment of short-term and working memory. Maximum admissible concentration (MAC for the inhalable fraction of silver of 0.05 mg/m3 is currently binding in Poland. In light of toxicological studies of silver nanoparticles it seems reasonable to update the hygiene standards for silver with nanoparticles as a separate fraction. Med Pr 2014;65(6:831–845

  15. Electromagnetic field induced biological effects in humans.

    Science.gov (United States)

    Kaszuba-Zwoińska, Jolanta; Gremba, Jerzy; Gałdzińska-Calik, Barbara; Wójcik-Piotrowicz, Karolina; Thor, Piotr J

    2015-01-01

    Exposure to artificial radio frequency electromagnetic fields (EMFs) has increased significantly in recent decades. Therefore, there is a growing scientific and social interest in its influence on health, even upon exposure significantly below the applicable standards. The intensity of electromagnetic radiation in human environment is increasing and currently reaches astronomical levels that had never before experienced on our planet. The most influential process of EMF impact on living organisms, is its direct tissue penetration. The current established standards of exposure to EMFs in Poland and in the rest of the world are based on the thermal effect. It is well known that weak EMF could cause all sorts of dramatic non-thermal effects in body cells, tissues and organs. The observed symptoms are hardly to assign to other environmental factors occurring simultaneously in the human environment. Although, there are still ongoing discussions on non-thermal effects of EMF influence, on May 31, 2011--International Agency for Research on Cancer (IARC)--Agenda of World Health Organization (WHO) has classified radio electromagnetic fields, to a category 2B as potentially carcinogenic. Electromagnetic fields can be dangerous not only because of the risk of cancer, but also other health problems, including electromagnetic hypersensitivity (EHS). Electromagnetic hypersensitivity (EHS) is a phenomenon characterized by the appearance of symptoms after exposure of people to electromagnetic fields, generated by EHS is characterized as a syndrome with a broad spectrum of non-specific multiple organ symptoms including both acute and chronic inflammatory processes located mainly in the skin and nervous systems, as well as in respiratory, cardiovascular systems, and musculoskeletal system. WHO does not consider the EHS as a disease-- defined on the basis of medical diagnosis and symptoms associated with any known syndrome. The symptoms may be associated with a single source of EMF

  16. Biological effect of radiation on human

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yun Sil; Cho, Chul Koo; Lee, Su Jae [and others

    2000-04-01

    1. Adaptive response when 0.01 Gy was preirradiated before high challenging dose is induced in normal cell types such normal lymphocytes, primary keratinocytes, and L929 fibroblast cells but not in neoplastic cells such as L5178Y lymphoma cells, EL-4 lymphoma cells and 308 papilloma cells. 2. Heat shock protein (HSP) 25 and inducible HSP70 is responsible for the induction of adaptive response and radioresistance - cell cycle regulation, antiapoptotic molecule and PKC activation were involved. 3. Apoptosis was induced at most 5. hrs after irradiation in primary keratinocytes, in v-rasHa transformed keratinocytes, the maximum interval was 16 hrs, and in 308 papilloma cells, the maximum was 48 hrs. 4. PKC response by radiation is correlated with induction of apoptosis. 5. Rapid induction PKCdelta in primary keratinocytes and no response of PKC epsilon may involved in radiation induced apoptosis. 6. The rate of resorption was increased when radiation was given at 2.5 days after gestation. Early death including foetal death were highly expressed when radiation was given at 7.5 days after gestation. There are no difference in incidence of late death including embryonic death. 7. 2 Gy is the most effective dose in radiation induced teratogenesis in mouse model. 8. Growth retardation and small head was present when radiation was given at 5.5, 7.5, 11.5 and 15.5 days after gestation and small head showed high incidence at 11.5 days after gestation. 9. External malformation, internal malformation and skeletal malformation was induced when radiation was given at 7.5 days after gestation. 10. OGG1-mutated cells induced radiosensitive by G2/M cell cycle arrest. 11. Radiation induced G2/M phase cell cycle and correlated with radiosensitivity. 12. PKCalpha induced differentiation. 13. Radiation exposed cells showed carcinogenic effect. 14. Organ specific radiosensitivity was shown and protein expression was involved.

  17. Biological effect of radiation on human

    International Nuclear Information System (INIS)

    Lee, Yun Sil; Cho, Chul Koo; Lee, Su Jae

    2000-04-01

    1. Adaptive response when 0.01 Gy was preirradiated before high challenging dose is induced in normal cell types such normal lymphocytes, primary keratinocytes, and L929 fibroblast cells but not in neoplastic cells such as L5178Y lymphoma cells, EL-4 lymphoma cells and 308 papilloma cells. 2. Heat shock protein (HSP) 25 and inducible HSP70 is responsible for the induction of adaptive response and radioresistance - cell cycle regulation, antiapoptotic molecule and PKC activation were involved. 3. Apoptosis was induced at most 5. hrs after irradiation in primary keratinocytes, in v-rasHa transformed keratinocytes, the maximum interval was 16 hrs, and in 308 papilloma cells, the maximum was 48 hrs. 4. PKC response by radiation is correlated with induction of apoptosis. 5. Rapid induction PKCdelta in primary keratinocytes and no response of PKC epsilon may involved in radiation induced apoptosis. 6. The rate of resorption was increased when radiation was given at 2.5 days after gestation. Early death including foetal death were highly expressed when radiation was given at 7.5 days after gestation. There are no difference in incidence of late death including embryonic death. 7. 2 Gy is the most effective dose in radiation induced teratogenesis in mouse model. 8. Growth retardation and small head was present when radiation was given at 5.5, 7.5, 11.5 and 15.5 days after gestation and small head showed high incidence at 11.5 days after gestation. 9. External malformation, internal malformation and skeletal malformation was induced when radiation was given at 7.5 days after gestation. 10. OGG1-mutated cells induced radiosensitive by G2/M cell cycle arrest. 11. Radiation induced G2/M phase cell cycle and correlated with radiosensitivity. 12. PKCalpha induced differentiation. 13. Radiation exposed cells showed carcinogenic effect. 14. Organ specific radiosensitivity was shown and protein expression was involved

  18. Induction of specific Escherichia coli genes by sublethal treatments with alkylating agents.

    OpenAIRE

    Volkert, M R; Nguyen, D C

    1984-01-01

    Fusions of the lac operon to genes induced by treatment with sublethal levels of alkylating agents have been selected from random insertions of the Mu-dl(ApRlac) phage by screening for induction of beta-galactosidase activity in the presence of methyl methanesulfonate. Genetic analysis reveals that these fusions resulted from insertion of Mu-dl(ApRlac) into two regions of the chromosome. One region (aidA) is near his and, based on phenotypic effects, appears to represent insertion into the al...

  19. The Biological Effects of Weak Electromagnetic Fields

    International Nuclear Information System (INIS)

    Algattawi, A.; Elshyrih, H.

    2010-01-01

    Many studies investigated that weak electromagnetic fields remove calcium ions bound to the membranes of living cells, making them more likely to tear,. There is an enzyme that destroys DNA this enzyme leaking through the membranes of lysosomes explains the fragmentation of DNA. This case was seen in cells exposed to mobile phone signals. When this occurs in the germ line it reduces fertility and predicts genetic damage in future generations. Although leakage of calcium ions into the cytosol (the main part of the cell) accelerates the growth, but it also promotes the growth of tumors. Leakage of calcium ions into neurons (brain cells) makes nerve impulses accounting for pain and other neurological symptoms in electro sensitive. It also reduces the signal to noise ratio of the brain making it less likely to respond. This may be partially responsible for the increased accident rate of drivers using mobile phones. More details for the molecular mechanisms to explain characteristics of electromagnetic exposure are needed, e.g. I) why weak fields are more effective than strong ones, II) why some frequencies such as 16 Hz are especially potent and III) why pulsed fields do more damage

  20. Air pollution. [Japan; man; biological effects

    Energy Technology Data Exchange (ETDEWEB)

    1975-01-01

    Air pollution levels in Japan are reported along with some resultant health effects. Photochemical smog first occurred in Tokyo during 1967. On July 18, 1970, more than 40 students at the Rissei Girl's High School were treated for eye irritation and throat pain caused by photochemical smog; during July 18 to August 5 of the same year, more than 10,000 injuries were reported. The proportion of the population in Yokkaichi with chronic bronchitis was extraordinarily high among those residents 40 yr or older. The 1-hour sulfur dioxide concentration was as high as 2.5 ppM in the early 1960's in the city. The carbon monoxide concentrations at busy intersections in Tokyo were 10 to 15 ppM. The average CO concentration at the Tokyo Municipal Office in 1969 was 10.6 ppM, and more than 50% of the measurements were higher than the environmental standard (1-hour average) of 10 ppM for 24 consecutive hr. Lead poisoning occurred at the Ushigome ward in Tokyo during the late 1960's and promoted the issuing of new regulations for lead-containing gasoline. (auth)

  1. Effects of air pollution on ecosystems and biological diversity in the eastern United States.

    Science.gov (United States)

    Lovett, Gary M; Tear, Timothy H; Evers, David C; Findlay, Stuart E G; Cosby, B Jack; Dunscomb, Judy K; Driscoll, Charles T; Weathers, Kathleen C

    2009-04-01

    elevated exposure levels or in combination with other stresses such as drought, freezing, or pathogens. The notable exceptions are the acid/aluminum effects on aquatic organisms, which can be lethal at levels of acidity observed in many surface waters in the region. Although the effects are often subtle, they are important to biological conservation. Changes in species composition caused by terrestrial or aquatic acidification or eutrophication can propagate throughout the food webs to affect many organisms beyond those that are directly sensitive to the pollution. Likewise, sublethal doses of toxic pollutants may reduce the reproductive success of the affected organisms or make them more susceptible to potentially lethal pathogens. Many serious gaps in knowledge that warrant further research were identified. Among those gaps are the effects of acidification, ozone, and mercury on alpine systems, effects of nitrogen on species composition of forests, effects of mercury in terrestrial food webs, interactive effects of multiple pollutants, and interactions among air pollution and other environmental changes such as climate change and invasive species. These gaps in knowledge, coupled with the strong likelihood of impacts on ecosystems that have not been studied in the region, suggests that current knowledge underestimates the actual impact of air pollutants on biodiversity. Nonetheless, because known or likely impacts of air pollution on the biodiversity and function of natural ecosystems are widespread in the Northeast and Mid-Atlantic regions, the effects of air pollution should be considered in any long-term conservation strategy. It is recommended that ecologically relevant standards, such as "critical loads," be adopted for air pollutants and the importance of long-term monitoring of air pollution and its effects is emphasized.

  2. Enhancements in biologically effective ultraviolet radiation following volcanic eruptions

    Science.gov (United States)

    Vogelmann, A. M.; Ackerman, T. P.; Turco, R. P.

    1992-01-01

    A radiative transfer model is used to estimate the changes in biologically effective radiation (UV-BE) at the earth's surface produced by the El Chichon (1982) and Mount Pinatubo (1991) eruptions. It is found that in both cases surface intensity can increase because the effect of ozone depletion outweighs the increased scattering.

  3. Biological effects of ionizing radiation at the molecular, cellular, and organismal levals. Triannual progress report, July 15, 1974--October 14, 1977

    International Nuclear Information System (INIS)

    Lange, C.S.

    1977-01-01

    Progress is reported on the following studies: organization and repair of DNA; size measurement of DNA by means of the ultracentrifuge; effects of hydroxyurea, cycloheximide, and methylmercury on cell cycle progression; absence of an effect of photoreactivation on sublethal damage repair in a photoreactivating Wallaby cell line; and the control of differentiation and tissue polarity in planarians

  4. Fipronil promotes motor and behavioral changes in honey bees (Apis mellifera) and affects the development of colonies exposed to sublethal doses.

    Science.gov (United States)

    Zaluski, Rodrigo; Kadri, Samir Moura; Alonso, Diego Peres; Martins Ribolla, Paulo Eduardo; de Oliveira Orsi, Ricardo

    2015-05-01

    Bees play a crucial role in pollination and generate honey and other hive products; therefore, their worldwide decline is cause for concern. New broad-spectrum systemic insecticides such as fipronil can harm bees and their use has been discussed as a potential threat to bees' survival. In the present study, the authors evaluate the in vitro toxicity of fipronil and note behavioral and motor activity changes in Africanized adult Apis mellifera that ingest or come into contact with lethal or sublethal doses of fipronil. The effects of sublethal doses on brood viability, population growth, behavior, and the expression of the defensin 1 gene in adult bees were studied in colonies fed with contaminated sugar syrup (8 µg fipronil L(-1) ). Fipronil is highly toxic to bees triggering agitation, seizures, tremors, and paralysis. Bees that are exposed to a lethal or sublethal doses showed reduced motor activity. The number of eggs that hatched, the area occupied by worker eggs, and the number of larvae and pupae that developed were reduced, adult bees showed lethargy, and colonies were abandoned when they were exposed to sublethal doses of fipronil. No change was seen in the bees' expression of defensin 1. The authors conclude that fipronil is highly toxic to honey bees and even sublethal doses may negatively affect the development and maintenance of colonies. © 2015 SETAC.

  5. Inductions of reproduction and population growth in the generalist predator Cyrtorhinus lividipennis (Hemiptera: Miridae) exposed to sub-lethal concentrations of insecticides.

    Science.gov (United States)

    Lu, Weiwei; Xu, Qiujing; Zhu, Jun; Liu, Chen; Ge, Linquan; Yang, Guoqing; Liu, Fang

    2017-08-01

    The miridbug, Cyrtorhinus lividipennis, is a significant predacious enemy of rice planthoppers. The effects of sub-lethal concentrations of triazophos, deltamethrin and imidacloprid on fecundity, egg hatchability, expression levels of genes associated with reproduction, and population growth in C. lividipennis were investigated. The fecundities for three pair combinations (♀ c × ♂ t , ♀ t × ♂ c and ♀ t × ♂ t ) treated with sub-lethal concentrations of the insecticides triazophos, deltamethrin and imidacloprid (LC 10 and LC 20 ) showed a significant increase compared to the untreated pairs (♀ c × ♂ c ). However, sub-lethal concentration treatments did not affect the egg hatchability. The ClVg expression levels of female adults exposed to triazophos, deltamethrin and imidacloprid (LC 20 ) increased by 52.6, 48.9 and 91.2%, respectively. The ClSPATA13 expression level of adult males exposed to triazophos, deltamethrim and imidacloprid (LC 20 ) increased by 80.7, 41.3 and 48.3%, respectively. Furthermore, sub-lethal concentrations of insecticides (LC 20 ) caused increased population numbers in C. lividipennis. Sub-lethal concentrations of triazophos, deltamethrin and imidacloprid stimulated reproduction and enhanced population growth of C. lividipennis. The reproductive stimulation might result from the up-regulation of ClVg or ClSPATA13. These findings may be useful in mediating populations of planthoppers. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  6. Bone effects of biologic drugs in rheumatoid arthritis.

    Science.gov (United States)

    Corrado, Addolorata; Neve, Anna; Maruotti, Nicola; Cantatore, Francesco Paolo

    2013-01-01

    Biologic agents used in the treatment of rheumatoid arthritis (RA) are able to reduce both disease activity and radiographic progression of joint disease. These drugs are directed against several proinflammatory cytokines (TNF α , IL-6, and IL-1) which are involved both in the pathogenesis of chronic inflammation and progression of joint structural damage and in systemic and local bone loss typically observed in RA. However, the role of biologic drugs in preventing bone loss in clinical practice has not yet clearly assessed. Many clinical studies showed a trend to a positive effect of biologic agents in preventing systemic bone loss observed in RA. Although the suppression of inflammation is the main goal in the treatment of RA and the anti-inflammatory effects of biologic drugs exert a positive effect on bone metabolism, the exact relationship between the prevention of bone loss and control of inflammation has not been clearly established, and if the available biologic drugs against TNF α , IL-1, and IL-6 can exert their effect on systemic and local bone loss also through a direct mechanism on bone cell metabolism is still to be clearly defined.

  7. The biologic effects of cigarette smoke on cancer cells.

    Science.gov (United States)

    Sobus, Samantha L; Warren, Graham W

    2014-12-01

    Smoking is one of the largest preventable risk factors for developing cancer, and continued smoking by cancer patients is associated with increased toxicity, recurrence, risk of second primary cancer, and mortality. Cigarette smoke (CS) contains thousands of chemicals, including many known carcinogens. The carcinogenic effects of CS are well established, but relatively little work has been done to evaluate the effects of CS on cancer cells. In this review of the literature, the authors demonstrate that CS induces a more malignant tumor phenotype by increasing proliferation, migration, invasion, and angiogenesis and by activating prosurvival cellular pathways. Significant work is needed to understand the biologic effect of CS on cancer biology, including the development of model systems and the identification of critical biologic mediators of CS-induced changes in cancer cell physiology. © 2014 American Cancer Society.

  8. Sublethal pesticide doses negatively affect survival and the cellular responses in American foulbrood-infected honeybee larvae

    Science.gov (United States)

    López, Javier Hernández; Krainer, Sophie; Engert, Antonia; Schuehly, Wolfgang; Riessberger-Gallé, Ulrike; Crailsheim, Karl

    2017-02-01

    Disclosing interactions between pesticides and bee infections is of most interest to understand challenges that pollinators are facing and to which extent bee health is compromised. Here, we address the individual and combined effect that three different pesticides (dimethoate, clothianidin and fluvalinate) and an American foulbrood (AFB) infection have on mortality and the cellular immune response of honeybee larvae. We demonstrate for the first time a synergistic interaction when larvae are exposed to sublethal doses of dimethoate or clothianidin in combination with Paenibacillus larvae, the causative agent of AFB. A significantly higher mortality than the expected sum of the effects of each individual stressor was observed in co-exposed larvae, which was in parallel with a drastic reduction of the total and differential hemocyte counts. Our results underline that characterizing the cellular response of larvae to individual and combined stressors allows unmasking previously undetected sublethal effects of pesticides in colony health.

  9. Third eye, the biological effects; 3. oeil, les effets biologiques

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-02-01

    The discovery of a third kind of photo-receptor cell in the human eye has permitted to better understand the biological effects of lighting, not only on the vision, but also on some nervous processes, like emotion, mood, stress, biological clock, etc.. This additional dimension has led the engineers of Philips Lighting company to launch a new indoor lighting concept named 'Carpe Diem'. This concept adapts both the illuminance and the color of a lighting system according to the type of work and to the expected stimulating effect. (J.S.)

  10. Biological effect of penetration controlled irradiation with ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi; Shimizu, Takashi; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Watanabe, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Yamashita, Takao

    1997-03-01

    To investigate the effect of local irradiation with ion beams on biological systems, technique for penetration controlled irradiation has been established. The range in a target was controlled by changing the distance from beam window in the atmosphere, and could be controlled linearly up to about 31 {mu}m in biological material. In addition, the effects of the penetration controlled irradiations with 1.5 MeV/u C and He ions were examined using tobacco pollen. The increased frequency of leaky pollen produced by ion beams suggests that the efficient pollen envelope damages would be induced at the range-end of ion beams. (author)

  11. Biological isotopy. Introduction to the isotopic effects and to their applications in biology

    International Nuclear Information System (INIS)

    Tcherkez, G.

    2010-01-01

    Since their discovery in the beginning of the 20. century, the study of stable isotopes has considerably developed. This domain, which remained limited in its applications until the 1990's, has become particularly important thereafter thanks to its practical applications and in particular to its economical impacts. Many techniques used in fraud control, in drugs use control, in selection of high-yield plants etc are based on isotopic abundance measurements. This reference book gives a synthesis of our actual knowledge on the use of stable isotopes and of isotope fractionation in biology. It presents the basic notions of isotopic biochemistry and explains the origin of the isotopic effects. The application principles of these effects to metabolism, to organisms physiology, to environmental biology etc are explained and detailed using examples and exercises. The first chapters present the basic knowledge which defines, from a mathematical point-of-view, the isotopic effects of chemical reactions or of physical processes taking place in biology. The measurements principle of natural isotopes abundance is then synthesised. Finally, all these notions are applied at different scales: enzymes, physiology, metabolism, environment, ecosystems and fraud crackdown. (J.S.)

  12. The relative biological effectiveness of out-of-field dose

    International Nuclear Information System (INIS)

    Balderson, Michael; Koger, Brandon; Kirkby, Charles

    2016-01-01

    Purpose: using simulations and models derived from existing literature, this work investigates relative biological effectiveness (RBE) for out-of-field radiation and attempts to quantify the relative magnitudes of different contributing phenomena (spectral, bystander, and low dose hypersensitivity effects). Specific attention is paid to external beam radiotherapy treatments for prostate cancer. Materials and methods: using different biological models that account for spectral, bystander, and low dose hypersensitivity effects, the RBE was calculated for different points moving radially out from isocentre for a typical single arc VMAT prostate case. The RBE was found by taking the ratio of the equivalent dose with the physical dose. Equivalent doses were calculated by determining what physical dose would be necessary to produce the same overall biological effect as that predicted using the different biological models. Results: spectral effects changed the RBE out-of-field less than 2%, whereas response models incorporating low dose hypersensitivity and bystander effects resulted in a much more profound change of the RBE for out-of-field doses. The bystander effect had the largest RBE for points located just outside the edge of the primary radiation beam in the cranial caudal (z-direction) compared to low dose hypersensitivity and spectral effects. In the coplanar direction, bystander effect played the largest role in enhancing the RBE for points up to 8.75 cm from isocentre. Conclusions: spectral, bystander, and low dose hypersensitivity effects can all increase the RBE for out-of-field radiation doses. In most cases, bystander effects seem to play the largest role followed by low dose hypersensitivity. Spectral effects were unlikely to be of any clinical significance. Bystander, low dose hypersensitivity, and spectral effect increased the RBE much more in the cranial caudal direction (z-direction) compared with the coplanar directions. (paper)

  13. The biological effects of low doses of radiation: medical, biological and ecological aspects

    International Nuclear Information System (INIS)

    Gun-Aajav, T.; Ajnai, L.; Manlaijav, G.

    2007-01-01

    Full text: The results of recent studies show that low doses of radiation make many different structural and functional changes in a cell and these changes are preserved for a long time. This phenomenon is called as effects of low doses of radiation in biophysics, radiation biology and radiation medicine. The structural and functional changes depend on doses and this dependence has non-linear and bimodal behaviour. More detail, the radiation effect goes up and reaches its maximum (Low doses maximum) in low doses region, then it goes down and takes its stationary means (there is a negative effect in a few cases). With increases in doses and with further increases it goes up. It is established that low dose's maximum depends on physiological state of a biological object, radiation quality and dose rate. During the experiments another special date was established. This specialty is that many different physical and chemical factors are mutually connected and have synergetic behaviour. At present, researches are concentrating their attention on the following three directions: 1. Direct and indirect interaction of radiation's low doses: 2. Interpretation of its molecular mechanism, regulation of the positive effects and elaboration of ways o removing negative effects: 3. Application of the objective research results into practice. In conclusion the authors mention the current concepts on interpretation of low doses effect mechanism, forward their own views and emphasize the importance of considering low doses effects in researches of environmental radiation pollution, radiation medicine and radiation protection. (author)

  14. The mechanism for the primary biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Byakov, Vsevolod M; Stepanov, Sergei V

    2006-01-01

    The primary biological response of living organisms to the passage of fast charged particles is traditionally believed to be dominated by the chemical reactions of the radical products from the radiolysis of cellular water (OH, H, e aq - , O 2 - , H 2 O 2 ) and by the bioradicals that they produce (and which can also result from the direct electronic activation of biomolecules). This understanding has provided insight into how ionizing radiations affect biological systems and, most importantly, what radioprotection and radiosensibilizing effects are produced by chemical compounds introduced into an organism. However, a number of key radiobiological facts remain unexplained by the current theory, stimulating a search for other biologically active factors that may be triggered by radiation. This review examines a fact that is usually ignored in discussing the biological impact of ionizing radiation: the local increase in acidity in the water solution along the track of a charged particle. The acidity in the track is very different from its value for cellular water in a living organism. Biological processes are well-known to be highly sensitive to changes in the environmental acidity. It seems that the biological impact of ionizing radiations is dominated not by the water radiolysis products (mostly radicals) listed above but particles of a different nature, hydroxonium ions H 3 O + , where the term hydroxonium refer to protonated water molecules. This modification of the mechanism of primary radiobiological effects is in good agreement with experimental data. In particular, the extremal dependence of the relative biological efficiency (RBE) of radiations on their ionizing energy losses is accounted for in quantitative terms, as is the increase in the RBE in the relativistic energy range. (reviews of topical problems)

  15. Physical and biological factors determining the effective proton range

    International Nuclear Information System (INIS)

    Grün, Rebecca; Friedrich, Thomas; Krämer, Michael; Scholz, Michael; Zink, Klemens; Durante, Marco; Engenhart-Cabillic, Rita

    2013-01-01

    Purpose: Proton radiotherapy is rapidly becoming a standard treatment option for cancer. However, even though experimental data show an increase of the relative biological effectiveness (RBE) with depth, particularly at the distal end of the treatment field, a generic RBE of 1.1 is currently used in proton radiotherapy. This discrepancy might affect the effective penetration depth of the proton beam and thus the dose to the surrounding tissue and organs at risk. The purpose of this study was thus to analyze the impact of a tissue and dose dependent RBE of protons on the effective range of the proton beam in comparison to the range based on a generic RBE of 1.1.Methods: Factors influencing the biologically effective proton range were systematically analyzed by means of treatment planning studies using the Local Effect Model (LEM IV) and the treatment planning software TRiP98. Special emphasis was put on the comparison of passive and active range modulation techniques.Results: Beam energy, tissue type, and dose level significantly affected the biological extension of the treatment field at the distal edge. Up to 4 mm increased penetration depth as compared to the depth based on a constant RBE of 1.1. The extension of the biologically effective range strongly depends on the initial proton energy used for the most distal layer of the field and correlates with the width of the distal penumbra. Thus, the range extension, in general, was more pronounced for passive as compared to active range modulation systems, whereas the maximum RBE was higher for active systems.Conclusions: The analysis showed that the physical characteristics of the proton beam in terms of the width of the distal penumbra have a great impact on the RBE gradient and thus also the biologically effective penetration depth of the beam

  16. Gulf of Mexico offshore operations monitoring experiment (GOOMEX), Phase I: Sublethal responses to contaminant exposure - introduction and overview

    International Nuclear Information System (INIS)

    Kennicutt, M. C.; Montagna, P.; Roscigno, P. F.

    1996-01-01

    An overview of a three-phase study to evaluate the range of biological, biochemical and chemical methodologies to detect and assess chronic sublethal biological impacts in the vicinity of long-duration activities in the Gulf of Mexico associated with oil and gas exploration and production, was provided. The basic program comprises four activities stretching over a two-year period, and is designed to detect nearfield impacts and contaminant gradients extending out of each of three sites. Sampling design includes a radial pattern with stations at intervals up to 3000 meters distant from the platform. The design employs a dose-response model to test the hypothesis that biological, biochemical and chemical variations are due to platform-derived contaminants. Detailed analysis of the contaminants includes analysis of sediments, pore waters and biological tissue, and assessment of community health based on life history and reproduction studies. 57 refs., 9 tabs., 5 figs

  17. Effects of hypervitaminosis of vitamin B3 on silkworm biology

    Indian Academy of Sciences (India)

    Unknown

    [Etebari K and Matindoost L 2004 Effects of hypervitaminosis of vitamin B3 on silkworm biology; J. Biosci. 29 417–422]. 1. ... ate growth of larvae and the reproduction in many insects and also mites has been ... were dried in air for 10 min.

  18. Nutrigenetic Effect of Moringa oleifera Seed Meal on the Biological ...

    African Journals Online (AJOL)

    Nutrigenetic Effect of Moringa oleifera Seed Meal on the Biological Growth Programme of Young Broiler Chickens. ... Asked Questions about PDFs. Alternatively, you can download the PDF file directly to your computer, from where it can be opened using a PDF reader. To download the PDF, click the Download link above.

  19. Radiation research contracts: Biological effects of small radiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Hug, O [International Atomic Energy Agency, Division of Health, Safety and Waste Disposal, Vienna (Austria)

    1959-04-15

    To establish the maximum permissible radiation doses for occupational and other kinds of radiation exposure, it is necessary to know those biological effects which can be produced by very small radiation doses. This particular field of radiation biology has not yet been sufficiently explored. This holds true for possible delayed damage after occupational radiation exposure over a period of many years as well as for acute reactions of the organism to single low level exposures. We know that irradiation of less than 25 Roentgen units (r) is unlikely to produce symptoms of radiation sickness. We have, however, found indications that even smaller doses may produce certain instantaneous reactions which must not be neglected

  20. Helicoverpa armigera (Lepidoptera: Noctuidae) larvae that survive sublethal doses of nucleopolyhedrovirus exhibit high metabolic rates.

    Science.gov (United States)

    Bouwer, Gustav; Nardini, Luisa; Duncan, Frances D

    2009-04-01

    To determine the effect of sublethal doses of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearSNPV) on the metabolic rate of H. armigera, the respiration rates of third instar H. armigera larvae inoculated with sublethal doses of HearSNPV were evaluated. Respiration rates, measured as the rate of CO(2) production (VCO(2)), were recorded daily using closed-system respirometry. By 4 days post-inoculation (dpi), the metabolic rates of LD(25) or LD(75) survivors were significantly higher than that of uninoculated controls. When dose data were pooled, the VCO(2) values of larvae that survived inoculation (0.0288mlh(-1)), the uninoculated controls (0.0250mlh(-1)), and the larvae that did not survive inoculation (0.0199mlh(-1)) differed significantly from one another. At 4dpi, the VCO(2) of the uninoculated controls were significantly lower than the VCO(2) of inoculation survivors, but significantly higher than the VCO(2) of inoculation non-survivors. Inoculation survivors may have had high metabolic rates due to a combination of viral replication, organ damage, and an energy-intensive induced cellular immune response. The high 4dpi metabolic rate of inoculation survivors may reflect an effective immune response and may be seen as the metabolic signature of larvae that are in the process of surviving inoculation with HearSNPV.

  1. Distribution and Biological Effects of Nanoparticles in the Reproductive System.

    Science.gov (United States)

    Liu, Ying; Li, Hongxia; Xiao, Kai

    2016-01-01

    Nanoparticles have shown great potential in biomedical applications such as imaging probes and drug delivery. However, the increasing use of nanoparticles has raised concerns about their adverse effects on human health and environment. Reproductive tissues and gametes represent highly delicate biological systems with the essential function of transmitting genetic information to the offspring, which is highly sensitive to environmental toxicants. This review aims to summarzie the penetration of physiological barriers (blood-testis barrier and placental barrier), distribution and biological effects of nanoparticles in the reproductive system, which is essential to control the beneficial effects of nanoparticles applications and to avoid their adverse effects on the reproductive system. We referred to a large number of relevant peer-reviewed research articles about the reproductive toxicity of nanoparticles. The comprehensive information was summarized into two parts: physiological barrier penetration and biological effects of nanoparticles in male or female reproductive system; distribution and metabolism of nanoparticles in the reproductive system. The representative examples were also presented in four tables. The in vitro and in vivo studies imply that some nanoparticles are able to cross the blood-testis barrier or placental barrier, and their penetration depends on the physicochemical characteristics of nanoparticles (e.g., composition, shape, particle size and surface coating). The toxicity assays indicate that nanoparticles might induce adverse physiological effects and impede fertility or embryogenesis. The barrier penetration, adverse physiological effects, distribution and metabolism are closely related to physicochemical characteristics of nanoparticles. Further systematic and mechanistic studies using well-characterized nanoparticles, relevant administration routes, and doses relevant to the expected exposure level are required to improve our

  2. Study of the effects of radon in three biological systems

    International Nuclear Information System (INIS)

    Tavera, L.; Balcazar, M.; Lopez, A.; Brena, M.; Rosa, M.E. De la; Villalobos P, R.

    2002-01-01

    The radon and its decay products are responsible of the 3/4 parts of the exposure of the persons to the environmental radiation. The discovery at the end of XIX Century of the illnesses, mainly of cancer, which appeared in the presence of radon, lead to an accelerated growing of the radon studies: monitoring, dosimetry, effects on the persons, etc. Several epidemiological studies of radon in miners and population in general have been realized; advancing in the knowledge about the concentration-lung cancer risk relationship, but with discrepancies in the results depending on the concentration levels. Therefor, studies which consuming time, efforts and money go on doing. The research of the radon effects in biological systems different to human, allows to realize studies in less time, in controlled conditions and generally at lower cost, generating information about the alpha radiation effects in the cellular field. Therefor it was decided to study the response of three biological systems exposed to radon: an unicellular bacteria Escherichia Coli which was exposed directly to alpha particles from an electrodeposited source for determining the sensitivity limit of the chose technique. A plant, Tradescantia, for studying the cytogenetic effect of the system exposed to controlled concentrations of radon. An insect, Drosophila Melanogaster, for studying the genetic effects and the accumulated effects in several generations exposed to radon. In this work the experimental settlements are presented for the expositions of the systems and the biological results commenting the importance of these. (Author)

  3. Radio-induced neuropathology: from early effects to late sequelae. Rat behavioural and metabolic studies after sublethal total body irradiation; Neuropathologie radio-induite: des effets precoces aux sequelles tardives. Etudes comportementales et metaboliques chez le rat apres irradiation globale subletale

    Energy Technology Data Exchange (ETDEWEB)

    Martigne, A.P.

    2010-05-15

    The radioresistance dogma of Central Nervous System (CNS) is now obsolete. Recent progress in neuroscience allow us to reconsider the radiation-induced cognitive dysfunctions observed after radiation therapy or after a nuclear accident, and to devise appropriate diagnostic and therapeutic means. We have developed a Rat model to study the effects of total body irradiation at a sublethal dose (4.5 Gy). This leads to impaired learning and memory of a task being acquired during the first month - which is prevented by administration of a radioprotector (amifostine) - while it does not appear to affect retrograde memory. Early, an apoptotic wave occurs in the sub-ventricular zone, 5 to 9 hours after exposure, while neuro-genesis is suppressed. Two days after irradiation, the metabolic study conducted by NMR HRMAS (High Resolution Magic Angle Spinning) suggests the presence of cerebral oedema and the study of brain lipids in liquid NMR confirms the membrane damages (elevated cholesterol and phospholipids). The lipid profile is then normalized while a gliosis appears. Finally, 1 month post-irradiation, the elevation of GABA, an inhibitory neurotransmitter, in 2 separate brain structures, occurs simultaneously with a taurine decrease in the hippocampus that lasts 6 months. Our integrated model allows validating bio-markers measurable in vivo NMR spectroscopy - the next experimental stage - and testing new radiation-protective agents. (author)

  4. Chemoradiotherapy and molecular biology

    International Nuclear Information System (INIS)

    Hasegawa, Masatoshi; Mitsuhashi, Norio; Niibe, Hideo

    2000-01-01

    The current status of chemoradiotherapy was reviewed from the standpoint of molecular biology. Chemoradiotherapy was conducted to achieve systemic tumor control, to intensify the response to irradiation, and to reduce adverse reactions. The mechanisms of the efficacy of chemoradiotherapy were: modification of dose-response relationships, inhibition of tumor cell recovery from sublethal damage or potential lethal damage, effects on cell dynamics and the cell cycle, improvement of blood flow or reoxygenation, recruitment, improvement of drug uptake, increased cell damage. Cell death (necrosis and apoptosis) and cancer-related genes were described, as the essential points, because they are involved in the response to chemoradiotherapy. Cisplatin (platinum compound), 5-fluorouracil, etoposide, and taxoid (paclitaxel, docetaxel) were the principal anticancer agents used for chemoradiotherapy, and they enhanced the effects of irradiation. However, even when good responses or synergism between anticancer drug and radiotherapy was observed in in vitro studies, there was little therapeutic advantage clinically. Data from in vitro and in vivo studies should be collected and systemized, and ''molecular biology in chemotherapy'' that can be applied clinically may become established. (K.H.)

  5. Evaluation of radiobiological effects in 3 distinct biological models

    International Nuclear Information System (INIS)

    Lemos, J.; Costa, P.; Cunha, L.; Metello, L.F.; Carvalho, A.P.; Vasconcelos, V.; Genesio, P.; Ponte, F.; Costa, P.S.; Crespo, P.

    2015-01-01

    Full text of publication follows. The present work aims at sharing the process of development of advanced biological models to study radiobiological effects. Recognizing several known limitations and difficulties of the current monolayer cellular models, as well as the increasing difficulties to use advanced biological models, our group has been developing advanced biological alternative models, namely three-dimensional cell cultures and a less explored animal model (the Zebra fish - Danio rerio - which allows the access to inter-generational data, while characterized by a great genetic homology towards the humans). These 3 models (monolayer cellular model, three-dimensional cell cultures and zebra fish) were externally irradiated with 100 mGy, 500 mGy or 1 Gy. The consequences of that irradiation were studied using cellular and molecular tests. Our previous experimental studies with 100 mGy external gamma irradiation of HepG2 monolayer cells showed a slight increase in the proliferation rate 24 h, 48 h and 72 h post irradiation. These results also pointed into the presence of certain bystander effects 72 h post irradiation, constituting the starting point for the need of a more accurate analysis realized with this work. At this stage, we continue focused on the acute biological effects. Obtained results, namely MTT and clonogenic assays for evaluating cellular metabolic activity and proliferation in the in vitro models, as well as proteomics for the evaluation of in vivo effects will be presented, discussed and explained. Several hypotheses will be presented and defended based on the facts previously demonstrated. This work aims at sharing the actual state and the results already available from this medium-term project, building the proof of the added value on applying these advanced models, while demonstrating the strongest and weakest points from all of them (so allowing the comparison between them and to base the subsequent choice for research groups starting

  6. Biological effects of transuranium elements in experimental animals

    International Nuclear Information System (INIS)

    Bair, W.J.

    1975-01-01

    Results are reported from life span studies of the biological effects of the transuranium elements ( 238 Pu, 239 Pu, 241 Am, and 242 Cm) on laboratory animals following inhalation, skin absorption, or injection in various chemical forms. The dose levels at which major biological effects have been observed in experimental animals are discussed relative to the maximum permissible lung burden of 0.016 μCi for occupational exposures. Lung cancer has been observed at dose levels equivalent to about 100 times the maximum permissible lung burden. Current experiments directed towards determining whether health effects will occur at lower levels and the mechanisms by which α emitters induce cancer are reviewed. (U.S.)

  7. Radiolabelled substrates for studying biological effects of trace contaminants

    International Nuclear Information System (INIS)

    1975-01-01

    A programme of coordinated isotopic tracer-aided investigations of the biological side-effects of foreign chemical residues in food and agriculture, initiated in 1973, was reviewed. The current status of representative investigations from the point of view of techniques and priorities was assessed. Such investigations involved radioactive substrates for studying DNA injury and its repair; 14 C-labelled acetylcholine as substrate for measuring enzyme inhibition due to the presence of, or exposure to, anticholinesteratic contaminants; radioactive substrates as indication of side-effects in non-target organisms and of their comparative susceptibilities; radioactive substrates as indicators of persistence or biodegradability of trace contaminants of soil or water; and labelled pools for studying the biological side-effects of trace contaminants. Priorities were identified

  8. Gene expression in Listeria monocytogenes exposed to sublethal concentration of benzalkonium chloride.

    Science.gov (United States)

    Tamburro, Manuela; Ripabelli, Giancarlo; Vitullo, Monia; Dallman, Timothy James; Pontello, Mirella; Amar, Corinne Francoise Laurence; Sammarco, Michela Lucia

    2015-06-01

    In this study, tolerance at sublethal concentration of benzalkonium chloride and transcription levels of mdrL, ladR, lde, sigB and bcrABC genes in Listeria monocytogenes strains were evaluated. Viable cells reduction occurred in 45% of strains and clinical isolates showed lower sensitivity than isolates from foods. An increased transcription of an efflux system encoding gene was found in 60% of strains, and simultaneous mdrL overexpression and ladR underexpression occurred in 30% of isolates. A significant association between reduced benzalkonium chloride activity and both mdrL and sigB overexpression was observed; sigB expression also correlated with both mdrL and ladR genes. The bcrABC gene was only found in six strains, all isolated from foods and sensitive to benzalkonium chloride, and in four strains an underexpression was observed. Disinfection at sublethal concentration was less effective in clinical isolates, and mdrL and sigB expression was significantly affected by disinfection. Further insights are needed to understand the adaptation to benzalkonium chloride and to evaluate whether changes in gene expression could affect the L. monocytogenes virulence traits and persistence in the environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Sublethal toxicity of nano-titanium dioxide and carbon nanotubes in a sediment dwelling marine polychaete

    Energy Technology Data Exchange (ETDEWEB)

    Galloway, Tamara, E-mail: t.s.galloway@exeter.ac.u [School of Biosciences, Hatherly Laboratories, University of Exeter, EX4 4PS, Exeter, Devon (United Kingdom); Lewis, Ceri [School of Biosciences, Hatherly Laboratories, University of Exeter, EX4 4PS, Exeter, Devon (United Kingdom); Dolciotti, Ida [Universita Politecnica delle Marche, Institute of Biology and Genetics, Via Ranieri, Monte Dago, 60121 Ancona (Italy); Johnston, Blair D. [School of Biosciences, Hatherly Laboratories, University of Exeter, EX4 4PS, Exeter, Devon (United Kingdom); Moger, Julian [School of Physics, Stocker Road, University of Exeter, Devon EX4 4QL (United Kingdom); Regoli, Francesco [Universita Politecnica delle Marche, Institute of Biology and Genetics, Via Ranieri, Monte Dago, 60121 Ancona (Italy)

    2010-05-15

    The ecotoxicology of manufactured nanoparticles (MNPs) in estuarine environments is not well understood. Here we explore the hypothesis that nanoTiO{sub 2} and single walled nanotubes (SWNT) cause sublethal impacts to the infaunal species Arenicola marina (lugworm) exposed through natural sediments. Using a 10 day OECD/ASTM 1990 acute toxicity test, no significant effects were seen for SWNT up to 0.03 g/kg and no uptake of SWNTs into tissues was observed. A significant decrease in casting rate (P = 0.018), increase in cellular damage (P = 0.04) and DNA damage in coelomocytes (P = 0.008) was measured for nanoTiO{sub 2}, with a preliminary LOEC of 1 g/kg. Coherent anti-stokes Raman scattering microscopy (CARS) located aggregates of TiO{sub 2} of >200 nm within the lumen of the gut and adhered to the outer epithelium of the worms, although no visible uptake of particles into tissues was detected. - This study explores the hypothesis that nano-TiO{sub 2} and single walled nanotubes (SWNT) can cause sublethal impacts to Arenicola marina exposed through natural sediments.

  10. Avoidance behaviour and anxiety in rats irradiated with a sublethal dose of gamma-rays.

    Science.gov (United States)

    Tomášová, Lenka; Smajda, B; Bona, M

    2011-12-01

    The aim of this study was to assess, whether a sublethal dose of gamma-rays will influence the avoidance behaviour and anxiety in rats and whether the response to radiation depends on time of day of its application. Adult male Wistar rats were tested in elevated plus-maze, in hot plate test and in the light/dark box in 4 regular intervals during a day. After two weeks the animals were irradiated with a whole-body dose 6 Gy of gamma-rays. One day after irradiation the animals were repeatedly tested in the same way, as before irradiation. In the plus-maze test an increased level of anxiety was established. The irradiation significantly decreased the locomotor activity of rats, but the extent of exploratory and comfortable behaviour were not altered. After irradiation, an elevated aversion to the thermal stimulus was observed in the hot plate test. The effects of radiation were more pronounced in the light period of the day, than in the dark one. No significant differences in aversion to light were detected after irradiation. The obtained results indicate, that sublethal doses of ionizing radiation can markedly influence the reactivity of animals to adverse stimuli, their motoric activity and emotional status, as well.

  11. Gene expression changes in honey bees induced by sublethal imidacloprid exposure during the larval stage.

    Science.gov (United States)

    Wu, Ming-Cheng; Chang, Yu-Wen; Lu, Kuang-Hui; Yang, En-Cheng

    2017-09-01

    Honey bee larvae exposed to sublethal doses of imidacloprid show behavioural abnormalities as adult insects. Previous studies have demonstrated that this phenomenon originates from abnormal neural development in response to imidacloprid exposure. Here, we further investigated the global gene expression changes in the heads of newly emerged adults and observed that 578 genes showed more than 2-fold changes in gene expression after imidacloprid exposure. This information might aid in understanding the effects of pesticides on the health of pollinators. For example, the genes encoding major royal jelly proteins (MRJPs), a group of multifunctional proteins with significant roles in the sustainable development of bee colonies, were strongly downregulated. These downregulation patterns were further confirmed through analyses using quantitative reverse transcription-polymerase chain reaction on the heads of 6-day-old nurse bees. To our knowledge, this study is the first to demonstrate that sublethal doses of imidacloprid affect mrjp expression and likely weaken bee colonies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Potential hepatic toxicity of buprofezin at sublethal concentrations: ROS-mediated conversion of energy metabolism.

    Science.gov (United States)

    Ji, Xiaotong; Ku, Tingting; Zhu, Na; Ning, Xia; Wei, Wei; Li, Guangke; Sang, Nan

    2016-12-15

    Buprofezin is known for its broad-spectrum action and environmental safety. The popularity of buprofezin has raised concerns about its potentially adverse effects on human health and risk to the environment. In this study, we first identified the liver as one of the major organs in which buprofezin accumulated, and we detected a severe oxidative stress response. Next, we demonstrated that sublethal concentrations of buprofezin promoted the conversion of energy metabolism from the aerobic tricarboxylic acid (TCA) cycle and oxidative phosphorylation to anaerobic glycolysis. Importantly, reactive oxygen species (ROS) generation partially accounted for the shunting of the energy metabolism through the buprofezin-mediated inhibition of cytochrome c oxidase activity. ROS directly perturbed the activities of several key TCA cycle enzymes, stimulated glycolysis, and indirectly disturbed the activity of the respiratory chain complex by altering mitochondrial DNA (mtDNA). These findings clarify the potential mechanisms of buprofezin toxicity and provide biomarkers for buprofezin-mediated hepatotoxicity at sublethal concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Extra lethal damage due to residual incompletely repaired sublethal damage in hyperfractionated and continuous radiation treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.; van de Geijn, J.; Goffman, T. (ROB, DCT, NCI, NIH, Bethesda, Maryland 20892 (US))

    1991-05-01

    In the conventional linear--quadratic model of single-dose response, the {alpha} and {beta} terms reflect lethal damage created {ital during} the delivery of a dose, from two different presumed molecular processes, one linear with dose, the other quadratic. With the conventional one-fraction-per-day (or less) regimens, the sublethal damage (SLD), presumably repairing exponentially over time, is essentially completely fixed by the time of the next dose of radiation. If this assumption is true, the effects of subsequent fractions of radiation should be independent, that is, there should be little, if any, reversible damage left from previous fractions, at the time of the next dose. For multiple daily fractions, or for the limiting case, continuous radiation, this simplification may overlook damaged cells that have had insufficient time for repair. A generalized method is presented for accounting for extra lethal damage (ELD) arising from such residual SLD for hyperfractionation and continuous irradiation schemes. It may help to predict differences in toxicity and tumor control, if any, obtained with unconventional'' treatment regimens. A key element in the present model is the finite size and the dynamic character of the pool of sublethal damage. Besides creating the usual linear and quadratic components of lethal damage, each new fraction converts a certain fraction of the existing SLD into ELD, and creates some new SLD.

  14. Extra lethal damage due to residual incompletely repaired sublethal damage in hyperfractionated and continuous radiation treatment

    International Nuclear Information System (INIS)

    Chen, J.; van de Geijn, J.; Goffman, T.

    1991-01-01

    In the conventional linear--quadratic model of single-dose response, the α and β terms reflect lethal damage created during the delivery of a dose, from two different presumed molecular processes, one linear with dose, the other quadratic. With the conventional one-fraction-per-day (or less) regimens, the sublethal damage (SLD), presumably repairing exponentially over time, is essentially completely fixed by the time of the next dose of radiation. If this assumption is true, the effects of subsequent fractions of radiation should be independent, that is, there should be little, if any, reversible damage left from previous fractions, at the time of the next dose. For multiple daily fractions, or for the limiting case, continuous radiation, this simplification may overlook damaged cells that have had insufficient time for repair. A generalized method is presented for accounting for extra lethal damage (ELD) arising from such residual SLD for hyperfractionation and continuous irradiation schemes. It may help to predict differences in toxicity and tumor control, if any, obtained with ''unconventional'' treatment regimens. A key element in the present model is the finite size and the dynamic character of the pool of sublethal damage. Besides creating the usual linear and quadratic components of lethal damage, each new fraction converts a certain fraction of the existing SLD into ELD, and creates some new SLD

  15. Does selective logging stress tropical forest invertebrates? Using fat stores to examine sublethal responses in dung beetles.

    Science.gov (United States)

    França, Filipe; Barlow, Jos; Araújo, Bárbara; Louzada, Julio

    2016-12-01

    The increased global demand for tropical timber has driven vast expanses of tropical forests to be selectively logged worldwide. While logging impacts on wildlife are predicted to change species distribution and abundance, the underlying physiological responses are poorly understood. Although there is a growing consensus that selective logging impacts on natural populations start with individual stress-induced sublethal responses, this literature is dominated by investigations conducted with vertebrates from temperate zones. Moreover, the sublethal effects of human-induced forest disturbance on tropical invertebrates have never been examined. To help address this knowledge gap, we examined the body fat content and relative abundance of three dung beetle species (Coleoptera: Scarabaeinae) with minimum abundance of 40 individuals within each examined treatment level. These were sampled across 34 plots in a before-after control-impact design (BACI) in a timber concession area of the Brazilian Amazon. For the first time, we present evidence of logging-induced physiological stress responses in tropical invertebrates. Selective logging increased the individual levels of fat storage and reduced the relative abundance of two dung beetle species. Given this qualitative similarity, we support the measurement of body fat content as reliable biomarker to assess stress-induced sublethal effects on dung beetles. Understanding how environmental modification impacts the wildlife has never been more important. Our novel approach provides new insights into the mechanisms through which forest disturbances impose population-level impacts on tropical invertebrates.

  16. Use of various acute, sublethal and early life-stage tests to evaluate the toxicity of refinery effluents

    International Nuclear Information System (INIS)

    Sherry, J.; Scott, B.; Dutka, B.

    1997-01-01

    The toxicities of effluents from three Ontario, Canada, refineries were assessed with microbes, plants, invertebrates, and fish. Acute toxicity was assessed by the Microtox test, an assay based on electron transport activity in submitochondrial particles, and Daphnia magna (water flea); growth of Selenastrum capricornutum (alga); growth of Lemna minor (aquatic plant); germination of Lactuca sativa (nonaquatic plant); survival, growth, and maturation of Panagrellus redivivus (nematode); and genotoxicity in the SOS-Chromotest. Only the Microtox test and the submitochondrial particle test detected acute toxicity in the effluent samples. Reduced survival and sublethal responses were caused by some effluents, but not all effluents were toxic, and none caused a response in all of the tests applied. The results suggest that the effluent treatment systems used at Ontario refineries have largely eliminated acute toxicity to the organisms in their test battery. Although reduced survival and sublethal effects were detected in some of the effluents, the effects were minor. Some of the tests provided evidence, albeit weak, of variations in the responses of the test organisms to a temporal series of effluent samples. Not unexpectedly, there were also minor differences in the responses of the tests to effluents from the three refineries. The fathead minnow test seems to be a sensitive indicator of the sublethal toxicity of Ontario refinery effluents

  17. [Biological effects of non-ionizing electromagnetic radiation].

    Science.gov (United States)

    Fedorowski, A; Steciwko, A

    1998-01-01

    Since the mid 1970's, when Adey discovered that extremely-low-frequency electromagnetic field (ELF EMF) may affect the calcium ions efflux from various cells, bioeffects of non-ionizing radiation (NIR) have become the subject of growing interest and numerous research projects. At present, the fact that NIR exerts both stimulatory and inhibitory effects on different physiological cellular parameters is rather unquestionable. At the same time, some epidemiological studies suggest that exposure to EMF is potentially harmful even if its intensity is very low. It has been proved that thermal factors are not responsible for these effects, therefore nowadays, they are called 'non-thermal effects'. Our paper deals with three different aspects of biological effects of non-ionizing radiation, bioelectromagnetism, electromagnetobiology and electromagnetic bioinformation. Firstly, we describe how EMF and photons can be produced within a living cell, how biological cycles are controlled, and what are the features of endogenous electromagnetic radiation. Secondly, we discuss various facets of external EMF interactions with living matter, focusing on extremely-low-frequencies, radio- and microwaves. Possible mechanisms of these interactions are also mentioned. Finally, we present a short overview of current theories which explain how electromagnetic couplings may control an open and dissipative structure, namely the living organism. The theory of electromagnetic bioinformation seems to explain how different physiological processes are triggered and controlled, as well as how long-range interactions may possibly occur within the complex biological system. The review points out that the presented research data must be assessed very carefully since its evaluation is crucial to set the proper limits of EMF exposure, both occupational and environmental. The study of biological effects of non-ioinizing radiation may also contribute to the development of new diagnostic and therapeutic

  18. Oxygen effect in radiation biology: caffeine and serendipity

    International Nuclear Information System (INIS)

    Kesavan, P.C.

    2005-01-01

    The 'hit theory' developed in 1920s to explain the actions of ionizing radiation on cells and organisms was purely physical, and its limitation was its inadequacy to address the contemporary findings such as the oxygen enhancement of radiobiological damage, and the increased radio- sensitivity of dividing compared to non-dividing cells. The textbooks written prior to 1970s did not either refer at all to oxygen as a radiosensitizer, or had mentioned it only in a passing manner; yet 'oxygen effect' was emerging as the central dogma in radiation biology. The oxygen effect in radiation biology is highly interdisciplinary encompassing atomic physics (i.e. interaction of photon with matter), radiation chemistry (formation of reactive oxygen species), molecular signalling, gene expression and genetic alterations in cells (mutation, cancer) or the cell death (apoptosis, necrosis, mitotic catastrophe, etc.). Cell death in higher organisms is now recognized as the precursor of possible error-free cell replacement repair. (author)

  19. Biological effect of nitrogen ion implantation on stevia

    International Nuclear Information System (INIS)

    Wang Cailian; Shen Mei; Chen Qiufang; Shu Shizhen

    1997-10-01

    Dry seed of stevia were implanted by 35∼150 keV nitrogen ions with various doses. The biological effect in M 1 was studied. The results showed that nitrogen ion beam was able to induce variation on chromosome structure in root tip cells. The rate of cells with chromosome aberration was increased with ion beam energy and dose added, but there was on significant linear regression relationship between ion dose and aberration rate. The results indicated the seedling height reduced with the increasing of dose for ion beam. The biological effect of nitrogen ion beam on M 1 stevia was lower than that of γ-rays. (6 refs., 1 fig., 4 tabs.)

  20. Advances in the biological effects of terahertz wave radiation.

    Science.gov (United States)

    Zhao, Li; Hao, Yan-Hui; Peng, Rui-Yun

    2014-01-01

    The terahertz (THz) band lies between microwave and infrared rays in wavelength and consists of non-ionizing radiation. Both domestic and foreign research institutions, including the army, have attached considerable importance to the research and development of THz technology because this radiation exhibits both photon-like and electron-like properties, which grant it considerable application value and potential. With the rapid development of THz technology and related applications, studies of the biological effects of THz radiation have become a major focus in the field of life sciences. Research in this field has only just begun, both at home and abroad. In this paper, research progress with respect to THz radiation, including its biological effects, mechanisms and methods of protection, will be reviewed.

  1. Importance of dose metrics for lethal and sublethal sediment metal toxicity in the oligochaete worm Lumbriculus variegatus

    Energy Technology Data Exchange (ETDEWEB)

    Penttinen, O.P.; Kilpi-Koski, J.; Toivainen, K. [Helsinki Univ., Lahti (Finland). Dept. of Ecology end Environmental Sciences; Jokela, M. [Mikkeli Univ. of Applied Sciences, Mikkeli (Finland); Vaeisaenen, A. [Jyvaeskylae Univ. (Finland). Dept. of Chemistry

    2008-02-15

    Background, aims, and scope. There is an increasing demand for controlled toxicity tests to predict biological effects related to sediment metal contamination. In this context, questions of metal-specific factors, sensitivity of toxicity endpoints, and variability in exposure duration arise. In addition, the choice of the dose metrics for responses is equally important and is related to the applicability of the concept of critical body residue (CBR) in exposure assessments, as well as being the main focus of this study. Methods. Experiments were conducted to assess toxicity of Cd, Cr, Cu and Pb to the oligochaete worm Lumbriculus variegatus with the aim of determining CBRs for two response metrics. Mortality and feeding activity of worms exposed to sediment-spiked metals were used as end-points in connection with residue analyses from both the organisms and the surrounding media. Results. LC50 values were 0.3, 1.4, 5.2, and 6.7 mg/L (from 4.7 {mu}mol/L to 128.0 {mu}mol/L), and the order of toxicity, from most toxic to least toxic, was Cu > Cd > Pb>Cr. By relating toxicity to body residue, variability in toxicity among the metals decreased and the order of toxicity was altered. The highest lethal residue value was obtained for Cu (10.8 mmol/kg) and the lowest was obtained for Cd (2.3 mmol/kg). In the 10-d sublethal test, both time and metal exposure were an important source of variation in the feeding activity of worms. The significant treatment effects were observed from worms exposed to Cd or Pb, with the controls yielding the highest feeding rate. However, quantitative changes in the measured end-point did not correlate with the exposure concentrations or body residues, which remained an order of magnitude lower than in the acute exposures. (orig.)

  2. Biological effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Gonzalez, A.J.

    1994-01-01

    Few weeks ago, when the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) submitted to the U.N. General Assembly the UNSCEAR 1994 report, the international community had at its disposal a broad view of the biological effects of low doses of ionizing radiation. The 1994 report (272 pages) specifically addressed the epidemiological studies of radiation carcinogenesis and the adaptive responses to radiation in cells and organisms. The report was aimed to supplement the UNSCEAR 1993 report to the U.N. General Assembly- an extensive document of 928 pages-which addressed the global levels of radiation exposing the world population, as well as some issues on the effects of ionizing radiation, including: mechanisms of radiation oncogenesis due to radiation exposure, influence of the level of dose and dose rate on stochastic effects of radiation, hereditary effects of radiation effects on the developing human brain, and the late deterministic effects in children. Those two UNSCEAR reports taken together provide an impressive overview of current knowledge on the biological effects of ionizing radiation. This article summarizes the essential issues of both reports, although it cannot cover all available information. (Author)

  3. Sub-Lethal Dose of Shiga toxin 2 from Enterohemorrhagic Escherichia coli Affects Balance and Cerebellar Cythoarquitecture.

    Directory of Open Access Journals (Sweden)

    Luciana eD’Alessio

    2016-02-01

    Full Text Available Shiga toxin producing Escherichia coli may damage the central nervous system before or concomitantly to manifested hemolytic uremic syndrome symptoms. The cerebellum is frequently damaged during this syndrome, however the deleterious effects of Shiga toxin 2 has never been integrally reported by ultrastructural, physiological and behavioral means. The aim of this study was to determine the cerebellar compromise after intravenous administration of a sub-lethal dose of Shiga toxin 2 by measuring the cerebellar blood brain barrier permeability, behavioral task of cerebellar functionality (inclined plane test, and ultrastructural analysis (transmission electron microscope. Intravenous administration of vehicle (control group, sub-lethal dose of 0.5 ηg and 1 ηg of Stx2 per mouse were tested for behavioral and ultrastructural studies. A set of three independent experiments were performed for each study (n=6. Blood–Brain Barrier resulted damaged and consequently its permeability was significantly increased. Lower scores obtained in the inclined plane task denoted poor cerebellar functionality in comparison to their controls. The most significant lower score was obtained after 5 days of 1ηg of toxin administration. Transmission electron microscope micrographs from the Stx2-treated groups showed neurons with a progressive neurodegenerative condition in a dose dependent manner. As sub-lethal intravenous Shiga toxin 2 altered the blood brain barrier permeability in the cerebellum the toxin penetrated the cerebellar parenchyma and produced cell damaged with significant functional implications in the test balance.

  4. Effect of Ceramic Scaffold Architectural Parameters on Biological Response

    Directory of Open Access Journals (Sweden)

    Maria Isabella eGariboldi

    2015-10-01

    Full Text Available Numerous studies have focused on the optimization of ceramic architectures to fulfill a variety of scaffold functional requirements and improve biological response. Conventional fabrication techniques, however, do not allow for the production of geometrically controlled, reproducible structures and often fail to allow the independent variation of individual geometric parameters. Current developments in additive manufacturing technologies suggest that 3D printing will allow a more controlled and systematic exploration of scaffold architectures. This more direct translation of design into structure requires a pipeline for design-driven optimization. A theoretical framework for systematic design and evaluation of architectural parameters on biological response is presented. Four levels of architecture are considered, namely (1 surface topography, (2 pore size and geometry, (3 porous networks and (4 macroscopic pore arrangement, including the potential for spatially varied architectures. Studies exploring the effect of various parameters within these levels are reviewed. This framework will hopefully allow uncovering of new relationships between architecture and biological response in a more systematic way, as well as inform future refinement of fabrication techniques to fulfill architectural necessities with a consideration of biological implications.

  5. Dosimetric characteristics of biological effect of sulfur-35

    International Nuclear Information System (INIS)

    Borisova, V.V.

    1990-01-01

    Experimental materials related to evaluation of dosimetric characteristics of sulfur-35 are presented. Hemogenic organs are subjected to greatest influence especially in the first hours after radionuclide entry into the organism. Comparison is made of absorbed doses in blood with observed blastomogen effect of hemogenic organs. It is noted, that quantitative evaluation of relative biological efficiency of low energy beta-emitters should be performed with account of dosimetric peculiarities of the nuclides mentioned above. 10 refs.; 3 tabs

  6. Biological effects of the ionizing radiation. Press breakfast

    International Nuclear Information System (INIS)

    Flury-Herard, A.; Boiteux, S.; Dutrillaux, B.; Toledano, M.

    2000-06-01

    This document brings together the subjects discussed during the Press breakfast of 29 june 2000 on the biological effects of the ionizing radiations, with scientists of the CEA and the CNRS. It presents the research programs and provides inquiries on the NDA operating to introduce the NDA damages by ionizing radiations, the possible repairs and the repair efficiency facing the carcinogenesis. Those researches allow the scientists to define laws on radiation protection. (A.L.B.)

  7. Metabolism and biological effects of alpha-emitting radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Bair, W. J.

    1979-05-01

    The emphasis of much of the current and planned research on the toxicity of alpha-emitting radionuclides is directed toward the complexities of actual and potential conditions of occupational environmental exposures of human beings. These, as well as the more limited studies on mechanisms of biological transport and effects, should increase our ability to predict health risks more accurately and to deal more confidently with human exposures, if and when they occur.

  8. Behavioral and Biological Effects of Resonant Electromagnetic Absorption in Rats.

    Science.gov (United States)

    1976-11-01

    for 23-550 MHz, biological phantom materials to simulate tissue properties, monopole -above-ground radiation chamber, design of a waveguide slot array...Resonant Electromagnetic Power Absorption in Rats" L T OF FTCTIF S A,’L i .LIS SFigure Pa 1 A photograiph of the monopole -above-gruund radiation...and mice without ground effects (L/2b = 3.25 where 21Tb is the "average" circumference of the animals) ........ .................... ... 20 8

  9. Biological activity of selected plants with adaptogenic effect

    OpenAIRE

    Eva Ivanišová; Miroslava Kačániová; Jana Petrová; Radka Staňková; Lucia Godočíková; Tomáš Krajčovič; Štefan Dráb

    2016-01-01

    The aim of this study was to determine biological activity of plants with adaptogenic effect: Panax ginseng Mayer., Withania somnifera L., Eleuterococcus senticosus Rupr. et Maxim., Astragallus membranaceus Fisch. and Codonopsis pilosulae Franch. The antioxidant activity was detected by DPPH and phosphomolybdenum method, total polyphenol content with Folin – Ciocalteu reagent, flavonoids content by aluminium chloride method. The detection of antimicrobial activity was carried out by disc diff...

  10. Comparison of ballistic impact effects between biological tissue and gelatin.

    Science.gov (United States)

    Jin, Yongxi; Mai, Ruimin; Wu, Cheng; Han, Ruiguo; Li, Bingcang

    2018-02-01

    Gelatin is commonly used in ballistic testing as substitute for biological tissue. Comparison of ballistic impact effects produced in the gelatin and living tissue is lacking. The work in this paper was aimed to compare the typical ballistic impact effects (penetration trajectory, energy transfer, temporary cavity) caused by 4.8mm steel ball penetrating the 60kg porcine hind limbs and 10wt% gelatin. The impact event in the biological tissue was recorded by high speed flash X-ray machine at different delay time, while the event in the gelatin continuously recorded by high speed video was compared to that in the biological tissue. The collected results clearly displayed that the ballistic impact effects in the muscle and gelatin were similar for the steel ball test; as for instance, the projectile trajectory in the two targets was basically similar, the process of energy transfer was highly coincident, and the expansion of temporary cavity followed the same pattern. This study fully demonstrated that choosing gelatin as muscle simulant was reasonable. However, the maximum temporary cavity diameter in the gelatin was a little larger than that in the muscle, and the expansion period of temporary cavity was longer in the gelatin. Additionally, the temporary cavity collapse process in the two targets followed different patterns, and the collapse period in the gelatin was two times as long as that in the muscle. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Biological effective dose studies in carcinoma of uterine cervix

    International Nuclear Information System (INIS)

    Yadav, Poonam; Ramasubramanian, V.

    2008-01-01

    Cancer of cervix is the second most common cancer worldwide among women. Several treatments related protocols of radiotherapy have been followed over few decades in its treatment for evaluating the response. These physical doses varying on the basics of fractionation size, dose rate and total dose needed to be indicated as biological effective dose (BED) to rationalize these treatments. The curative potential of radiation therapy in the management of carcinoma of the cervix is greatly enhanced by the use of intracavitary brachytherapy. Successful brachytherapy requires the high radiation dose to be delivered to the tumor where as minimum radiation dose reach to surrounding normal tissue. Present study is aimed to evaluate biologically effective dose in patients receiving high dose-rate brachytherapy plus external beam radiotherapy based on tumor cell proliferation values in cancer of the cervix patients. The study includes 30 patients' data as a retrospective analysis. In addition determine extent of a dose-response relationship existing between the biological effective dose at Point A and the bladder and rectum and the clinical outcomes

  12. The biological effectiveness of heavy ion radiations in the environment

    International Nuclear Information System (INIS)

    Craven, P.A.

    1996-03-01

    Although heavy ions are rarely encountered in the majority of terrestrial environments, the exposure of humans to this fascinating class of ionizing radiation is becoming more frequent. Long-duration spaceflight, new radiotherapeutic procedures and enhanced levels of radon, and other naturally-occurring alpha particle emitters, have all increased concern and stimulated interest recently within the radiological protection and radiobiological communities. Significant data concerning the long-term effects of low levels of heavy ions on mammalian systems are correspondingly scarce, leading to increased emphasis on modelling all aspects of the radiation-organism interaction. Contemporary radiation protection procedures reflect the need for a more fundamental understanding of the mechanisms responsible for the biological actions of such radiations. Major deficiencies exist in the current recommendations for assessment of relative effectiveness, the enhanced severity of the biological consequences instigated by heavy ions, over conventional sparsely ionizing radiations. In an attempt to remedy some of the inadequate concepts and assumptions presently employed and, simultaneously, to gain insight into the fundamental mechanisms behind the notion of radiation quality, a series of algorithms have been developed and executed as computer code, to evaluate the biological effectiveness of heavy ion radiation ''tracks'' according to a number of criteria. These include consideration of the spatial characteristics of physical energy deposition in idealised cellular structures (finite particle range, radial extension of tracks via δ-ray emission) and the likelihood of induction and mis-repair of severe molecular lesions (double-strand breaks, multiply-damaged sites). (author)

  13. Cytogenetic measurements of the relative biological effectiveness of tritium

    International Nuclear Information System (INIS)

    Chopra, C.; Heddle, J.A.

    1988-10-01

    Chromosome aberrations in peripheral blood lymphocytes, which are used to estimate radiation dose biologically, were induced by tritium 1.14 times as effectively as X-rays (95% confidence limits: 0.8 - 1.5). Chromosome translocations in spermatogonia, which are one component of genetic risk, were induced by tritium 1.21 times as effectively as X-rays (95% confidence limits: 0.8 -1.9). All experimental measurements were made in CBA/H mice injected with tritiated water or exposed to X-rays at a comparable dose rate

  14. Biological effects of ionizing radiation - changing worker attitudes

    International Nuclear Information System (INIS)

    Johnson, N.; Schenley, C.

    1989-01-01

    Training Resources and Data Exchange (TRADE) Radiation Protection Training Special Interest Group has taken an innovative approach to providing DOE contractors with radiation worker training material information. Newly-hired radiation workers may be afraid to work near radiation and long-term radiation workers may become indifferent to the biological hazard of radiation. Commercially available training material is often presented at an inappropriate technical level or in an uninteresting style. These training problems have been addressed in the DOE system through development of a training videotape and supporting material package entitled Understanding Ionizing Radiation and its Biological Effects. The training package, developed and distributed by TRADE specifically to meet the needs of DOE contractor facilities, contains the videotape and accompanying paper supporting materials designed to assist the instructor. Learning objectives, presentation suggestion for the instructor, trainee worksheets, guided discussion questions, and trainee self-evaluation sheets are included in the training package. DOE contractors have agreed that incorporating this training module into radiation worker training programs enhances the quality of the training and increase worker understanding of the biological effects of ionizing radiation

  15. Estimation of biological effects of phytocenosis radioactive contamination

    International Nuclear Information System (INIS)

    Suvorova, L.I.; Smirnov, E.G.; Shejn, G.N.

    1990-01-01

    Biological effects of argicultural field contamination in the Chernobyl NPP 30-km zone in the period of 1986-1988 are studies. Depth of some kings of herbs is noted in spite of natural phytocenosis high stability. It is revealed that increased mutageneous effect is observed for seeds from phytocenosis subjected to radiation factor effects. The genetic radiation effects at cell level will be observed in the nearest years as the radiation factor will not disappear in the 30-km zone (chronic irradiation of plants in the dose range from 0.1x10 -4 up to 0.1 Gy/day). These injuries visually will not effect greatly on natural populations

  16. The Effects Of Physical And Biological Cohesion On Bedforms

    Science.gov (United States)

    Parsons, D. R.; Schindler, R.; Baas, J.; Hope, J. A.; Malarkey, J.; Paterson, D. M.; Peakall, J.; Manning, A. J.; Ye, L.; Aspden, R.; Alan, D.; Bass, S. J.

    2014-12-01

    Most coastal sediments consist of complex mixtures of cohesionless sands, physically-cohesive clays and extra cellular polymeric substances (EPS) that impart biological cohesion. Yet, our ability to predict bedform dimensions in these substrates is reliant on predictions based exclusively on cohesionless sand. We present findings from the COHBED project - which explicitly examines how bedform dynamics are modified by natural cohesion. Our experimental results show that for ripples, height and length are inversely proportional to initial clay content and bedforms take longer to appear, with no ripples when clay content exceeds 18%. When clay is replaced by EPS the development time and time of first appearance of ripples both increase by two orders of magnitude, with no bedforms above 0.125% EPS. For dunes, height and length are also inversely proportional to initial substrate clay content, resulting in a transition from dunes to ripples normally associated with velocity decreases. Addition of low EPS concentrations into the substrate results in yet smaller bedforms at the same clay contents and at high EPS concentrations, biological cohesion supersedes all electrostatic bonding, and bedform size is no longer related to mud content. The contrast in physical and biological cohesion effects on bedform development result from the disparity between inter-particle electrostatic bonding of clay particles and EPS grain coating and strands that physically link sediments together, which effects winnowing rates as bedforms evolve. These findings have wide ranging implications for bedform predictions in both modern and ancient environments. Coupling of biological and morphological processes not only requires an understanding of how bedform dimensions influence biota and habitat, but also how benthic species can modify bedform dimensions. Consideration of both aspects provides a means in which fluid dynamics, sediment transport and ecosystem energetics can be linked to yield

  17. Sublethal concentrations of ichthyotoxic alga Prymnesium parvum affect rainbow trout susceptibility to viral haemorrhagic septicaemia virus

    DEFF Research Database (Denmark)

    Andersen, Nikolaj Gedsted; Lorenzen, Ellen; Boutrup, Torsten Snogdal

    2016-01-01

    Ichthyotoxic algal blooms are normally considered a threat to maricultured fish only when blooms reach lethal cell concentrations. The degree to which sublethal algal concentrations challenge the health of the fish during blooms is practically unknown. In this study, we analysed whether sublethal...

  18. Assessment of the biological effects of 'strange' radiation

    International Nuclear Information System (INIS)

    Pryakhin, E.A.; Tryapitsina, G.A.; Urutskoyev, L.I.; Akleyev, A.V.

    2006-01-01

    The results from studies of the effects produced by electrical explosions of foils made from super pure materials in water point to the emergence of new chemical elements. An additional finding was the discharge of 'strange' radiation accompanying the transformation of chemical elements. However, currently, the mechanism involved in the interaction between 'strange' radiation and a substance or a biological entity remains obscure. Therefore, the aim of the present research is to investigate the biological effects of the 'strange' radiation. Pilot studies were performed at the RECOM RRC 'Kurchatov Institute' in April-May of 2004. The animals used in the experiment were female mice of C57Bl/6 line aged 80 days with body weight 16-18 g. The animals were exposed to radiation discharged during explosions of Ti foils in water and aqueous solutions. The cages with animals were placed at 1 m from the epicenter of the explosion. Explosions were carried out on the 19. (3 explosions), 20. (4 explosions) and 22. (3 explosions) of April, 2004 (explosions No1373 - No1382, respectively). The animals were assigned to 4 experimental groups comprised of 17-20 mice per group. The animals received experimental exposure within 1, 2 and 3 days of the experiment. In total, the experimental groups were exposed to 3, 7 and 10 explosions, respectively. In order to identify the biological reactions, the following parameters were estimated: number of nucleated cells in the bone marrow, number of CFU in the spleen after additional gamma-irradiation (6 Gy), cell composition of the bone marrow, the rate of erythrocytes with the different level of maturation in the bone marrow, the rate of erythrocytes with the micronuclei in the bone marrow, the reaction of bone marrow cells to additional gamma-irradiation (2 Gy), number of leucocytes in the peripheral blood, and cell composition of the peripheral blood. The following conclusions were drawn from these studies: 1. 'strange' radiation resulting

  19. Far infrared radiation (FIR): its biological effects and medical applications.

    Science.gov (United States)

    Vatansever, Fatma; Hamblin, Michael R

    2012-11-01

    Far infrared (FIR) radiation (λ = 3-100 μm) is a subdivision of the electromagnetic spectrum that has been investigated for biological effects. The goal of this review is to cover the use of a further sub-division (3- 12 μm) of this waveband, that has been observed in both in vitro and in vivo studies, to stimulate cells and tissue, and is considered a promising treatment modality for certain medical conditions. Technological advances have provided new techniques for delivering FIR radiation to the human body. Specialty lamps and saunas, delivering pure FIR radiation (eliminating completely the near and mid infrared bands), have became safe, effective, and widely used sources to generate therapeutic effects. Fibers impregnated with FIR emitting ceramic nanoparticles and woven into fabrics, are being used as garments and wraps to generate FIR radiation, and attain health benefits from its effects.

  20. Health and biological effects of non-ionizing radiations

    International Nuclear Information System (INIS)

    De Seze, R.; Souques, M.; Aurengo, A.; Bach, V.; Burais, N.; Cesarini, J.P.; Cherin, A.; Decobert, V.; Dubois, G.; Hours, M.; Lagroye, I.; Leveque, Ph.; Libert, J.P.; Lombard, J.; Loos, N.; Mir, L.; Perrin, A.; Poulletier De Gannes, F.; Thuroczy, G.; Wiart, J.; Lehericy, St.; Pelletier, A.; Marc-Vergnes, J.P.; Douki, Th.; Guibal, F.; Tordjman, I.; Gaillot de Saintignon, J.; Collard, J.F.; Scoretti, R.; Magne, I.; Veyret, B.; Katrib, J.

    2011-01-01

    This document gathers the slides of the available presentations given during this conference day on the biological and health effects of non-ionizing radiations. Sixteen presentations out of 17 are assembled in the document and deal with: 1 - NMR: biological effects and implications of Directive 2004/40 on electromagnetic fields (S. Lehericy); 2 - impact of RF frequencies from mobile telephone antennas on body homeostasis (A. Pelletier); 3 - expression of stress markers in the brain and blood of rats exposed in-utero to a Wi-Fi signal (I. Lagroye); 4 - people exposure to electromagnetic waves: the challenge of variability and the contribution of statistics to dosimetry (J. Wiart); 5 - status of knowledge about electromagnetic fields hyper-sensitivity (J.P. Marc-Vergnes; 6 - geno-toxicity of UV radiation: respective impact of UVB and UVA (T. Douki); 7 - National day of prevention and screening for skin cancers (F. Guibal); 8 - UV tan devices: status of knowledge about cancer risks (I. Tordjman, and J. Gaillot de Saintignon); 9 - modulation of brain activity during a tapping task after exposure to a 3000 μT magnetic field at 60 Hz (M. Souques and A. Legros); 10 - calculation of ELF electromagnetic fields in the human body by the finite elements method (R. Scoretti); 11 - French population exposure to the 50 Hz magnetic field (I. Magne); 12 - LF and static fields, new ICNIRP recommendations: what has changed, what remains (B. Veyret); 13 - risk assessment of low energy lighting systems - DELs and CFLs (J.P. Cesarini); 14 - biological effects to the rat of a chronic exposure to high power microwaves (R. De Seze); 15 - theoretical and experimental electromagnetic compatibility approaches of active medical implants in the 10-50 Hz frequency range: the case of implantable cardiac defibrillators (J. Katrib); French physicians and electromagnetic fields (M. Souques). (J.S.)

  1. A Review: Some biological effects of high LET radiations

    Science.gov (United States)

    Wiley, A., Jr.

    1972-01-01

    There are qualitative and quantitative differences in the biological damage observed after exposure to high LET radiation as compared to that caused by low LET radiations. This review is concerned with these differences, which are ultimately reflected at the biochemical, cellular and even whole animal levels. In general, high LET radiations seem to produce biochemical damage which is more severe and possibly less repairable. Experimental data for those effects are presented in terms of biochemical RBE's with consideration of both early and late manifestations. An LET independent process by which significant biochemical damage may result from protons, neutrons and negative pion mesons is discussed.

  2. Effective Elastic Modulus of Structured Adhesives: From Biology to Biomimetics

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2017-06-01

    Full Text Available Micro- and nano-hierarchical structures (lamellae, setae, branches, and spatulae on the toe pads of many animals play key roles for generating strong but reversible adhesion for locomotion. The hierarchical structure possesses significantly reduced, effective elastic modulus (Eeff, as compared to the inherent elastic modulus (Einh of the corresponding biological material (and therefore contributes to a better compliance with the counterpart surface. Learning from nature, three types of hierarchical structures (namely self-similar pillar structure, lamella–pillar hybrid structure, and porous structure have been developed and investigated.

  3. Uranium: properties and biological effects after internal contamination

    International Nuclear Information System (INIS)

    Souidi, M.; Tissandie, E.; Racine, R.; Ben Soussan, H.; Rouas, C.; Grignard, E.; Dublineau, I.; Gourmelon, P.; Lestaevel, P.; Gueguen, Y.

    2009-01-01

    Uranium is a radionuclide present in the environment since the origin of the Earth. In addition to natural uranium, recent deposits from industrial or military activities are acknowledged. Uranium's toxicity is due to a combination of its chemical (heavy metal) and radiological properties (emission of ionizing radiations). Acute toxicity induces an important weight loss and signs of renal and cerebral impairment. Alterations of bone growth, modifications of the reproductive system and carcinogenic effects are also often seen. On the contrary, the biological effects of a chronic exposure to low doses are unwell known. However, results from different recent studies suggest that a chronic contamination with low levels of uranium induces subtle but significant levels. Indeed, an internal contamination of rats for several weeks leads to detection of uranium in many cerebral structures, in association with an alteration of short-term memory and an increase of anxiety level. Biological effects of uranium on the metabolisms of xenobiotics, steroid hormones and vitamin D were described in the liver, testis and kidneys. These recent scientific data suggest that uranium could participate to increase of health risks linked to environmental pollution. (authors)

  4. Biological effects and medical applications of infrared radiation.

    Science.gov (United States)

    Tsai, Shang-Ru; Hamblin, Michael R

    2017-05-01

    Infrared (IR) radiation is electromagnetic radiation with wavelengths between 760nm and 100,000nm. Low-level light therapy (LLLT) or photobiomodulation (PBM) therapy generally employs light at red and near-infrared wavelengths (600-100nm) to modulate biological activity. Many factors, conditions, and parameters influence the therapeutic effects of IR, including fluence, irradiance, treatment timing and repetition, pulsing, and wavelength. Increasing evidence suggests that IR can carry out photostimulation and photobiomodulation effects particularly benefiting neural stimulation, wound healing, and cancer treatment. Nerve cells respond particularly well to IR, which has been proposed for a range of neurostimulation and neuromodulation applications, and recent progress in neural stimulation and regeneration are discussed in this review. The applications of IR therapy have moved on rapidly in recent years. For example, IR therapy has been developed that does not actually require an external power source, such as IR-emitting materials, and garments that can be powered by body heat alone. Another area of interest is the possible involvement of solar IR radiation in photoaging or photorejuvenation as opposites sides of the coin, and whether sunscreens should protect against solar IR? A better understanding of new developments and biological implications of IR could help us to improve therapeutic effectiveness or develop new methods of PBM using IR wavelengths. Copyright © 2016. Published by Elsevier B.V.

  5. Review: Bioenergetic Fields and Their Biologic Effects Mechanism

    Directory of Open Access Journals (Sweden)

    Zahra Movaffaghi

    2007-04-01

    Full Text Available As interests in complementary and alternative medicine grows, the scientists are looking forward in researches which determine the mechanisms in which they exert their effectiveness. Some of these modalities like Yoga, Acupuncture, and especially other bio-field therapies such as none contact therapeutic touch, affects the bio-field which spreads throughout the body and into the space around it. According to physic’s law, when electricity flows throw the living tissues, like what happens in our heart and brain, biomagnetic fields are being induced in the surrounding space. Beside that moving charges like ions and free radicals which finally produce electromagnetic fields. Using very sensitive magnetometers, biomagnetic fields have been detected and get amplified up to 1000 times by meditation. This phenomenon could be the basis for most of most complementaty therapeutic approaches like therapeutic touch. On the other hand the electrical, magnetic and bio-magnetic fields have a well known application in conventional medicine. Modern research about bio-magnetism and magneto-biology suggests that in term of both aspects, the effects and the mechanisms for all the different looking modalities used in conventional medicine and complementary medicine which have commons in their fundamentals. This article reviews some of the recent works on biological effects of natural or artificial electromagnetic fields.

  6. Sublethal Toxic Effects and Induction of gGutathione S-transferase by Short-Chain Chlorinated Paraffins (SCCPs) and C-12 alkane (dodecane) in Xenopus laevis Frog Embryos

    OpenAIRE

    B. Burýšková; L. Bláha; D. Vršková; K. Šimková; B. Maršálek

    2006-01-01

    Short chain chlorinated paraffins (SCCPs) are important industrial chemicals with high persistence in the environment but poorly characterized ecotoxicological effects. We studied embryotoxic effects of commercial mixture of SCCP (carbon length C-12, 56% of chlorine; CP56-12) and non-chlorinated n-alkane (dodecane, C-12) in the 96h Frog Embryo Teratogenesis Assay - Xenopus (FETAX). Only weak lethal effects were observed for both substances (the highest tested concentration 500 mg/L of both ch...

  7. Biological activity of selected plants with adaptogenic effect

    Directory of Open Access Journals (Sweden)

    Eva Ivanišová

    2016-05-01

    Full Text Available The aim of this study was to determine biological activity of plants with adaptogenic effect: Panax ginseng Mayer., Withania somnifera L., Eleuterococcus senticosus Rupr. et Maxim., Astragallus membranaceus Fisch. and Codonopsis pilosulae Franch. The antioxidant activity was detected by DPPH and phosphomolybdenum method, total polyphenol content with Folin – Ciocalteu reagent, flavonoids content by aluminium chloride method. The detection of antimicrobial activity was carried out by disc diffusion method against three species of Gram-negative bacteria: Escherichia coli CCM 3988, Salmonella enterica subsp. enterica CCM 3807, Yersinia enterocolitica CCM 5671 and two Gram-positive bacteria: Bacillus thuringiensis CCM 19, Stapylococcus aureus subsp. aureus CCM 2461. Results showed that plants with adaptogenic effect are rich for biologically active substances. The highest antioxidant activity by DPPH method was determined in the sample of Eleuterococcus senticosus (3.15 mg TEAC – Trolox equivalent antioxidant capacity per g of sample and by phosphomolybdenum method in the sample of Codonopsis pilosulae (188.79 mg TEAC per g of sample. In the sample of Panax ginseng was measured the highest content of total polyphenols (8.10 mg GAE – galic acid equivalent per g of sample and flavonoids (3.41 μg QE – quercetin equivalent per g of sample. All samples also showed strong antimicrobial activity with the best results in Panax ginseng and Withania somnifera in particular for species Yersinia enterocolitica CCM 5671 and Salmonella enterica subsp. enterica CCM 3807. The analyzed species of plant with high value of biological activity can be used more in the future, not only in food, but also in cosmetics and pharmaceutical industries.

  8. The effect of biological cohesion on current ripple development

    Science.gov (United States)

    Malarkey, Jonathan; Baas, Jaco H.; Hope, Julie

    2014-05-01

    Results are presented from laboratory experiments examining the role of biological cohesion, associated with Extra Polymeric Substances, on the development of current ripples. The results demonstrate the importance of biological cohesion compared to the effect of physical cohesion associated with clays in an otherwise sandy bed. FURTHER INFORMATION In fluvial and marine environments sediment transport is mainly dependent on the nature of the bed surface (rippled or flat) and the nature of cohesion in the bed. Cohesion can be either physical, as a result of the presence of clays, or biological as a result of the presence of organisms. In the case of the latter, biological cohesion occurs as a result of the presence of Extra Polymeric Substances (EPS) secreted by microorganisms. While it is known that EPS can dramatically increase the threshold of motion (Grant and Gust, 1987), comparatively little is known about the effect of EPS on ripple formation and development. The experiments described here seek to fill this gap. They also allow the effect of biological cohesion to be compared with that of physical cohesion from previous experiments (Baas et al., 2013). The experiments, which were conducted in a 10m flume at Bangor University, involved a current over a bed made of fine sand, with a median diameter of 0.148mm, and various amounts of xanthan gum, a proxy for naturally occurring EPS (Vardy et al., 2007). The hydrodynamic experimental conditions were matched very closely to those of Baas et al. (2013). The ripple dimensions were recorded through the glass side wall of the tank using time lapse photography. In the physical cohesion experiments of Baas et al. (2013) for clay contents up to 12%, the clay was very quickly winnowed out of the bed, leaving essentially clay-free ripples that developed at more or less the same rate as clean sand ripples. The resulting equilibrium ripples were essentially the same length as the clean sand ripples but reduced in height. By

  9. Sublethal Toxic Effects and Induction of gGutathione S-transferase by Short-Chain Chlorinated Paraffins (SCCPs and C-12 alkane (dodecane in Xenopus laevis Frog Embryos

    Directory of Open Access Journals (Sweden)

    B. Burýšková

    2006-01-01

    Full Text Available Short chain chlorinated paraffins (SCCPs are important industrial chemicals with high persistence in the environment but poorly characterized ecotoxicological effects. We studied embryotoxic effects of commercial mixture of SCCP (carbon length C-12, 56% of chlorine; CP56-12 and non-chlorinated n-alkane (dodecane, C-12 in the 96h Frog Embryo Teratogenesis Assay - Xenopus (FETAX. Only weak lethal effects were observed for both substances (the highest tested concentration 500 mg/L of both chemicals caused up to 11% mortality. On the other hand, we observed developmental malformations and reduced embryo growth at 5 mg/l and higher concentrations. However, the effects were not related to chlorination pattern as both SCCPs and dodecane induced qualitatively similar effects. SCCPs also significantly induced phase II detoxification enzyme glutathione S-transferase (GST in Xenopus laevis embryos even at 0.5 mg/L, and this biomarker might be used as another early warning of chronic toxic effects. Our results newly indicate significant developmental toxicity of both SCCPs and n-dodecane to aquatic organisms along with inductions of specific biochemical toxicity mechanisms.

  10. The biological effects of radium-224 injected into dogs

    International Nuclear Information System (INIS)

    Muggenburg, B.A.; Hahn, F.F.; Boecker, B.B.

    1996-01-01

    A life-span study was conducted in 128 beagle dogs to determine the biological effects of intravenously injected 224 Ra chloride. The 224 Ra chloride was prepared by the same method used for intravenous injections in humans who were treated for ankylosing spondylitis and tuberculosis. Thus the results obtained from dogs can be compared directly to the population of treated humans, both for the elucidation of the effect of exposure rate and for comparison with other radionuclides for which data for humans are unavailable. Using equal numbers of males and females, the dogs were injected with one of four levels of 224 Ra resulting in initial body burdens of approximately 13, 40, 120 or 350 kBq of 224 Ra kg -1 body mass. A control group of dogs was injected with diluent only. All dogs were divided further into three groups for which the amount of injected 224 Ra (half-life of 3.62 days) or diluent was given in a single injection or divided equally into 10 or 50 weekly injections. As a result of these three injection schedules, the accumulation of dose from the injected 224 Ra was distributed over approximately 1, 3 or 12 months. Each injection schedule included four different injection levels resulting in average absorbed α-particle doses to bone of 0.1, 0.3, 1 and 3 Gy, respectively. The primary early effect observed was a hematological dyscrasia in the dogs receiving either of the two highest injection levels. The effect was most severe in the dogs receiving a single injection of 224 Ra and resulted in the death of three dogs injected at the highest level. The late-occurring biological effects were tumors. Bone tumors were the most common followed by tumors in the nasal mucosa. 52 refs., 8 figs., 8 tabs

  11. BIOLOGICAL EFFECTS OF MICROWAVE RADIATION ON BRAIN TISSUE IN RATS

    Directory of Open Access Journals (Sweden)

    Boris Đinđić

    2003-04-01

    Full Text Available Exposure to microwave radiation induces multiple organ dysfunctions, especially in CNS.The aim of this work was investigation of biological effects of microwave radiation on rats' brain and determination of increased oxidative stress as a possible pathogenetic's mechanism.Wis tar rats 3 months old were divided in experimental (4 female and 4 male animal and control group (5 female and 4 male. This experimental group was constantly exposed to a magnetic field of 5 mG. We simulated using of mobile phones 30 min every day. The source of NIR emitted MF that was similar to mobile phones at 900 MHz. The rats were killed after 2 months. Biological effects were determined by observation of individual and collective behavior and body mass changes. Lipid per oxidation was determined by measuring quantity of malondialdehyde (MDA in brain homogenate.The animals in experimental group exposed to EMF showed les weight gain. The most important observations were changing of basic behavior models and expression of aggressive or panic behavior. The content of MDA in brain tissue is singificantly higher (1.42 times in rats exposed to electromagnetic fields (3,82±0.65 vs. control 2.69±0.42 nmol/mg proteins, p<0.01.Increased oxidative stress and lipid peroxidation after exposition in EM fields induced disorders of function and structure of brain.

  12. Hafnium oxide nanoparticles: toward an in vitro predictive biological effect?

    International Nuclear Information System (INIS)

    Marill, Julie; Anesary, Naeemunnisa Mohamed; Zhang, Ping; Vivet, Sonia; Borghi, Elsa; Levy, Laurent; Pottier, Agnes

    2014-01-01

    Hafnium oxide, NBTXR3 nanoparticles were designed for high dose energy deposition within cancer cells when exposed to ionizing radiation. The purpose of this study was to assess the possibility of predicting in vitro the biological effect of NBTXR3 nanoparticles when exposed to ionizing radiation. Cellular uptake of NBTXR3 nanoparticles was assessed in a panel of human cancer cell lines (radioresistant and radiosensitive) by transmission electron microscopy. The radioenhancement of NBTXR3 nanoparticles was measured by the clonogenic survival assay. NBTXR3 nanoparticles were taken up by cells in a concentration dependent manner, forming clusters in the cytoplasm. Differential nanoparticle uptake was observed between epithelial and mesenchymal or glioblastoma cell lines. The dose enhancement factor increased with increase NBTXR3 nanoparticle concentration and radiation dose. Beyond a minimum number of clusters per cell, the radioenhancement of NBTXR3 nanoparticles could be estimated from the radiation dose delivered and the radiosensitivity of the cancer cell lines. Our preliminary results suggest a predictable in vitro biological effect of NBTXR3 nanoparticles exposed to ionizing radiation

  13. Biological effects of ionizing radiation; Efectos biologicos de la radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Gisone, Pablo; Perez, Maria R [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina)

    2001-07-01

    It has been emphasised the importance of DNA as the main target for ionizing radiation, that can induce damage by its direct action on this molecule or by an indirect effect mediated by free-radicals generated by water radiolysis. Biological effects of ionizing radiation are influenced not only by the dose but also by the dose-rate and the radiation quality. Radiation induced damage, mainly DNA single and double strand breaks, is detected by molecular sensors which in turn trigger signalling cascades leading to cell cycle arrest to allow DNA repair or programmed cell death (apoptosis). Those effects related with cell death, named deterministic, exhibits a dose-threshold below which they are not observed. Acute radiation syndrome and radiological burns are examples of this kind of effects. Other radiation induced effects, called stochastic, are the consequence of cell transformation and do not exhibit a dose-threshold. This is the case of cancer induction and hereditary effects. The aim of this presentation is briefly describe the main aspects of deterministic and stochastic effects from the point of view of radiobiology and radio pathology. (author)

  14. Biological interactions and human health effects of static magnetic fields

    International Nuclear Information System (INIS)

    Tenforde, T.S.

    1994-09-01

    Mechanisms through which static magnetic fields interact with living systems will be described and illustrated by selected experimental observations. These mechanisms include electrodynamic interactions with moving ionic charges (blood flow and nerve impulse conduction), magnetomechanical interactions (orientation and translation of molecular structures and magnetic particles), and interactions with electronic spin states in charge transfer reactions (photo-induced electron transfer in photosynthesis). A general summary will also be presented of the biological effects of static magnetic fields studied in the laboratory and in natural settings. One aspect of magnetic field effects that merits special concern is their influence on implanted medical electronic devices such as cardiac pacemakers. Several extensive studies have demonstrated closure of the reed switch in pacemakers exposed to relatively weak static magnetic fields, thereby causing them to revert to an asynchronous mode of operation that is potentially hazardous. Recommendations for human exposure limits are provided

  15. Arsenic in the aquatic environment - speciation and biological effects

    Energy Technology Data Exchange (ETDEWEB)

    Landner, L [Swedish Environmental Research Group (MFG)

    1998-03-01

    The present report is a contribution to EC Commission`s undertaking to review existing EC provisions on the substances for which Sweden has been granted transitional provisions. The provisions imply that Sweden may maintain more stringent regulations on four substances until the end of 1998. The present report deals with speciation and biological effects of arsenic in three types of aquatic environments - marine water, estuarine or brackish water and freshwater. The similarity between arsenate and phosphate and the interference in phosphorylation reactions is discussed. It is clear that in Scandinavian inland waters the concentration of phosphorous is on average lower than in most inland waters in continental Europe. However, in most inland waters phosphorus is the limiting factor for phytoplankton development and eutrophication, which means that there is a clear risk for detrimental effects in the great majority of inland waters, also eutrophic waters 167 refs, 27 figs, 12 tabs. Exemption Substances Project (Directive 89/677/EEC)

  16. Relative biological effectiveness of protons and heavy particles

    International Nuclear Information System (INIS)

    Vyglenov, A.; Fedorenko, B.; Kabachenko, A.

    1986-01-01

    The genetic effectiveness was studied of protons (9 GeB/nuclon, 0,72 Gy/min), α-particles (4 GeB/nuclon, 0,9 Gy/min) and carbon ions (4 GeB/nuclon 0,36 Gy/min). The translocation yield in mouse spermatogonia was used as indicator of radiation-induced genetic injury. Reciprocal translocation were registered six months after the irradiation on spermatocytes in diakinesmetaphase I. Comparison was made with gamma-irradiated animals from 60 Co source with dose rate 1,44 Gy/min. The relative biological effectiveness (RBE) was determined by comparing the regression coefficients from the linear dose translocation yield dependency. The values of the RBE coefficients were 0.8, 0.9 and 1.2, accordingly for protons, α-particles and carbon ions

  17. Changes in liver glycogen reserve in Wistar rats as a result of polysaccharide treatment and single sublethal gamma-irradiation

    International Nuclear Information System (INIS)

    Metodiev, S.; Lambov, V.; Pavlova, N.

    1993-01-01

    The phase changes in the quantity of liver glycogen after single sublethal irradiation are investigated. The lowest concentration levels are registered at days 1, 3, 8 and 13 post irradiation. The effect of polysaccharide radioresistance modulation on the liver glycogen concentration is evaluated. The subcutaneous polysaccharide application of the immuno-active product PL prevents the sharp decrease of the liver glycogen concentration level, as a result of radiation provoked damages. The polysaccharide protection is most effective 5 - 21 days after irradiation. The conclusions are based on enzymic and hystomorphological studies. (author)

  18. Hepatic regeneration after sublethal partial liver irradiation in cirrhotic rats

    International Nuclear Information System (INIS)

    Gu Ke; Lai Songtao; Ma Ningyi; Zhao Jiandong; Ren Zhigang; Wang Jian; Liu Jin; Jiang Guoliang

    2011-01-01

    Our previous animal study had demonstrated that partial liver irradiation (IR) could stimulate regeneration in the protected liver, which supported the measurements adopted in radiotherapy planning for hepatocellular carcinoma. The purpose of this present study is to investigate whether cirrhotic liver repopulation could be triggered by partial liver IR. The cirrhosis was induced by thioacetamide (TAA) in rats. After cirrhosis establishment, TAA was withdrawn. In Experiment 1, only right-half liver was irradiated with single doses of 5 Gy, 10 Gy and 15 Gy, respectively. In Experiment 2, right-half liver was irradiated to 15 Gy, and the left-half to 2.5 Gy, 5 Gy and 7.5 Gy, respectively. The regeneration endpoints, including liver index (LI); mitotic index (MI); liver proliferation index (LPI); proliferating cell nuclear antigen-labeling index (PCNA-LI); serum hepatic growth factor (HGF), vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-α and interleukin (IL)-6, were evaluated on 0 day, 30-day, 60-day, 90-day, 120-day and 150-day after IR. Serum and in situ TGF-β1 were also measured. In both experimental groups, the IR injuries were sublethal, inducing no more than 9% animal deaths. Upon TAA withdrawal, hepatic regeneration decelerated in the controls. In Experiment 1 except for LI, all other regeneration parameters were significantly higher than those in controls for both right-half and left-half livers. In Experiment 2 all regeneration parameters were also higher compared with those in controls for both half livers. Serum HGF and VEGF were increased compared with that of controls. Both unirradiated and low dose-irradiated cirrhotic liver were able to regenerate triggered by sublethal partial liver IR and higher doses and IR to both halves liver triggered a more enhanced regeneration. (author)

  19. Late biological effects from internal and external exposure

    International Nuclear Information System (INIS)

    Adams, W.H.

    1985-01-01

    Information on late biological effects of radiation was obtained from the long-term medical followup of a small population of Marshallese accidentally exposed to radioactive fallout from a thermonuclear test in 1954. Endocrine data are compatible with a sequence of nonstochastic radiation effects. The ingestion of radioisotopes of iodine produced clinical thyroid hypofunction in children, biochemical evidence of thyroid dysfunction in some adults, thyroid adenomatous module formation, and, as a possible indirect effect of thyroid damage, at least two cases of pituitary adenoma. In contrast, the only evidence of a stochastic effect has been a real increase in thyroid cancers among the more highly exposed people of Rongelap, none of whom have evidence of residual disease. While three nonthyroidal cancers which are known to be inducible in humans by external irradiation have been documented in the exposed population, three similar cancers have occurred in an unexposed comparison population of Marshallese. Nonstochastic effects of radiation exposure may be common but subtle. In the Marshallese experience the morbidity of delayed nonstochastic effects far exceeds that of the stochastic. 20 refs., 5 figs., 1 tab

  20. Enhanced Biological Phosphorus Removal : Metabolic Insights and Salinity Effects

    NARCIS (Netherlands)

    Welles, L.

    2015-01-01

    Enhanced biological phosphorus removal (EBPR) is a biological process for efficient phosphate removal from wastewaters through intracellular storage of polyphosphate by polyphosphate-accumulating organisms (PAO) and subsequent removal of PAO from the system through wastage of sludge. In comparison

  1. Exposure to Sublethal Doses of Fipronil and Thiacloprid Highly Increases Mortality of Honeybees Previously Infected by Nosema ceranae

    Science.gov (United States)

    Vidau, Cyril; Diogon, Marie; Aufauvre, Julie; Fontbonne, Régis; Viguès, Bernard; Brunet, Jean-Luc; Texier, Catherine; Biron, David G.; Blot, Nicolas; El Alaoui, Hicham; Belzunces, Luc P.; Delbac, Frédéric

    2011-01-01

    Background The honeybee, Apis mellifera, is undergoing a worldwide decline whose origin is still in debate. Studies performed for twenty years suggest that this decline may involve both infectious diseases and exposure to pesticides. Joint action of pathogens and chemicals are known to threaten several organisms but the combined effects of these stressors were poorly investigated in honeybees. Our study was designed to explore the effect of Nosema ceranae infection on honeybee sensitivity to sublethal doses of the insecticides fipronil and thiacloprid. Methodology/Finding Five days after their emergence, honeybees were divided in 6 experimental groups: (i) uninfected controls, (ii) infected with N. ceranae, (iii) uninfected and exposed to fipronil, (iv) uninfected and exposed to thiacloprid, (v) infected with N. ceranae and exposed 10 days post-infection (p.i.) to fipronil, and (vi) infected with N. ceranae and exposed 10 days p.i. to thiacloprid. Honeybee mortality and insecticide consumption were analyzed daily and the intestinal spore content was evaluated 20 days after infection. A significant increase in honeybee mortality was observed when N. ceranae-infected honeybees were exposed to sublethal doses of insecticides. Surprisingly, exposures to fipronil and thiacloprid had opposite effects on microsporidian spore production. Analysis of the honeybee detoxification system 10 days p.i. showed that N. ceranae infection induced an increase in glutathione-S-transferase activity in midgut and fat body but not in 7-ethoxycoumarin-O-deethylase activity. Conclusions/Significance After exposure to sublethal doses of fipronil or thiacloprid a higher mortality was observed in N. ceranae-infected honeybees than in uninfected ones. The synergistic effect of N. ceranae and insecticide on honeybee mortality, however, did not appear strongly linked to a decrease of the insect detoxification system. These data support the hypothesis that the combination of the increasing

  2. Recovery from sublethal damage during fractionated irradiation of human FaDu SCC

    International Nuclear Information System (INIS)

    Petersen, Cordula; Zips, Daniel; Krause, Mechthild; Voelkel, Wolfram; Thames, Howard D.; Baumann, Michael

    2005-01-01

    Background and purpose: The present study addresses whether recovery of sublethal damage in tumours may change during fractionated irradiation in FaDu human squamous cell carcinoma and whether such an effect might contribute to the pronounced time factor of fractionated irradiation previously found in this tumour. Patients and methods: FaDu tumours were transplanted s.c. into the right hind leg of NMRI nu/nu mice. Single doses or 2, 4, and 8 equal fractions in 3.5 days were applied in previously unirradiated tumours and after priming with 18 fractions of 3 Gy in 18 or 36 days. All irradiations were given under clamp hypoxic conditions. Experimental endpoints were tumour control dose 50% (TCD 50 ) and α/β values without and after priming. Results: Without priming TCD 50 increased with increasing number of fractions from 38.8 Gy (95% CI 35;45) after single dose irradiation to 54.0 Gy (42;57) after 8 fractions. No increase in TCD 50 when given in 1, 2, 4, or 8 fractions in 3.5 days was found after priming with 18 3-Gy fractions in 18 and 36 days. After priming with 18 fractions in 18 days TCD 50 remained constant at 25 Gy and after priming with 18 fractions in 36 days at 42 Gy. The α/β ratio without priming was 68 Gy (42;127). After fractionated irradiation with 18 3-Gy fractions in 18 and 36 days the α/β ratio increased to 317 Gy (38;∞) and to infinite, respectively. Conclusions: Our results indicate that clonogenic cells in FaDu tumours lose entirely their capacity to recover from sublethal radiation damage during fractionated irradiation. Therefore, an increased repair capacity as an explanation for the pronounced time factor of fractionated irradiation in this tumour can be ruled out

  3. Chemical and biological effects of radiation sterilization of medical products

    International Nuclear Information System (INIS)

    Gupta, B.L.

    1975-01-01

    Radiation is extensively used for the sterilization of plastic materials, pharmaceuticals and biological tissue grafts. The pharmaceuticals may be solid, liquid, or suspension in a liquid or a solution. Cobalt-60 gamma radiation, generally used for sterilization, primarily interacts with these materials through the Compton process. The resulting damage may be direct or indirect. In aqueous systems the primary species produced compete for interaction among themselves and the dissolved solutes. The nature, the G-values and the reactions of the primary species very much depend on the pH of the solution. The important chemical changes in plastic materials are gas liberation, change in concentration of double bonds, cross-linking, degradation and oxidation. These chemical changes lead to some physical changes like crystallinity, specific conductivity and permeability. The reactions in biological systems are very complex and are influenced by the presence or absence of water and oxygen. Water produces indirect damage and the radiation effect is generally more in the presence of oxygen. Most microorganisms are relatively radioresistant. Various tissues of an animal differ in their response to radiation. Catgut is not stable to irradiation. Lyophilized human serum is stable to irradiation whereas, when irradiated in aqueous solutions, several changes are observed. Generally, pharmaceuticals are considerably more stable in the dry solid state to ionizing radiations than in aqueous solutions or in any other form of molecular aggregation. (author)

  4. Biological vs. physical mixing effects on benthic food web dynamics.

    Directory of Open Access Journals (Sweden)

    Ulrike Braeckman

    Full Text Available Biological particle mixing (bioturbation and solute transfer (bio-irrigation contribute extensively to ecosystem functioning in sediments where physical mixing is low. Macrobenthos transports oxygen and organic matter deeper into the sediment, thereby likely providing favourable niches to lower trophic levels (i.e., smaller benthic animals such as meiofauna and bacteria and thus stimulating mineralisation. Whether this biological transport facilitates fresh organic matter assimilation by the metazoan lower part of the food web through niche establishment (i.e., ecosystem engineering or rather deprives them from food sources, is so far unclear. We investigated the effects of the ecosystem engineers Lanice conchilega (bio-irrigator and Abra alba (bioturbator compared to abiotic physical mixing events on survival and food uptake of nematodes after a simulated phytoplankton bloom. The (13C labelled diatom Skeletonema costatum was added to 4 treatments: (1 microcosms containing the bioturbator, (2 microcosms containing the bio-irrigator, (3 control microcosms and (4 microcosms with abiotic manual surface mixing. Nematode survival and subsurface peaks in nematode density profiles were most pronounced in the bio-irrigator treatment. However, nematode specific uptake (Δδ(13C of the added diatoms was highest in the physical mixing treatment, where macrobenthos was absent and the diatom (13C was homogenised. Overall, nematodes fed preferentially on bulk sedimentary organic material rather than the added diatoms. The total C budget (µg C m(-2, which included TO(13C remaining in the sediment, respiration, nematode and macrobenthic uptake, highlighted the limited assimilation by the metazoan benthos and the major role of bacterial respiration. In summary, bioturbation and especially bio-irrigation facilitated the lower trophic levels mainly over the long-term through niche establishment. Since the freshly added diatoms represented only a limited food

  5. Biological effects of particles from the paris subway system.

    Science.gov (United States)

    Bachoual, Rafik; Boczkowski, Jorge; Goven, Delphine; Amara, Nadia; Tabet, Lyes; On, Dinhill; Leçon-Malas, Véronique; Aubier, Michel; Lanone, Sophie

    2007-10-01

    Particulate matter (PM) from atmospheric pollution can easily deposit in the lungs and induce recruitment of inflammatory cells, a source of inflammatory cytokines, oxidants, and matrix metalloproteases (MMPs), which are important players in lung structural homeostasis. In many large cities, the subway system is a potent source of PM emission, but little is known about the biological effects of PM from this source. We performed a comprehensive study to evaluate the biological effects of PM sampled at two sites (RER and Metro) in the Paris subway system. Murine macrophages (RAW 264.7) and C57Bl/6 mice, respectively, were exposed to 0.01-10 microg/cm2 and 5-100 microg/mouse subway PM or reference materials [carbon black (CB), titanium dioxide (TiO2), or diesel exhaust particles (DEPs)]. We analyzed cell viability, production of cellular and lung proinflammatory cytokines [tumor necrosis factor alpha (TNFalpha), macrophage inflammatory protein (MIP-2), KC (the murin analog of interleukin-8), and granulocyte macrophage-colony stimulating factor (GM-CSF)], and mRNA or protein expression of MMP-2, -9, and -12 and heme oxygenase-1 (HO-1). Deferoxamine and polymixin B were used to evaluate the roles of iron and endotoxin, respectively. Noncytotoxic concentrations of subway PM (but not CB, TiO2, or DEPs) induced a time- and dose-dependent increase in TNFalpha and MIP-2 production by RAW 264.7 cells, in a manner involving, at least in part, PM iron content (34% inhibition of TNF production 8 h after stimulation of RAW 264.7 cells with 10 microg/cm2 RER particles pretreated with deferoxamine). Similar increased cytokine production was transiently observed in vivo in mice and was accompanied by an increased neutrophil cellularity of bronchoalveolar lavage (84.83+/-0.98% of polymorphonuclear neutrophils for RER-treated mice after 24 h vs 7.33+/-0.99% for vehicle-treated animals). Subway PM induced an increased expression of MMP-12 and HO-1 both in vitro and in vivo. PM from the

  6. Migration of bone marrow cells to the thymus in sublethally irradiated mice

    International Nuclear Information System (INIS)

    Varlet, Andree; Lenaerts, Patrick; Houben-Defresne, M.P.; Boniver, Jacques

    1982-01-01

    In sublethally irradiated mice, thymus repopulation is due first to the proliferation of surviving thymocytes followed by the multiplication of bone marrow derived prothymocytes. The migration of bone marrow cells to the thymus after a single sublethal whole-body X irradiation was studied by using fluorescein isothiocyanate as a cell marker. Irradiation increases the permissiveness of the thymus to the immigration of bone marrow cells. Furthermore, the post-Rx regenerating bone marrow cells exhibit migration capacities greater than the normal ones. The radiation induced changes in the bone marrow thymus interaction might play an important role in thymus regeneration after sublethal irradiation [fr

  7. The relative biological effectiveness of radiations of different quality

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This paper is a review of the literature relevant to the selection of relative biological effectiveness (RBE) values for use in arriving at values of the quality factor (Q). Emphasis is placed on response to small ( M . In a wide variety of systems, the RBE M for fast (fission) neutrons, with low doses and dose rates, appears to be of the order of 20 or more compared to moderately filtered 250 kVp x rays and 40 or more compared to higher energy gamma rays. These values, which are much larger than those observed with large doses delivered at high dose rates, are due mainly, but not entirely, to a decrease in the slope of the curve for the ow-LET reference radiation at low dose

  8. Interaction mechanisms and biological effects of static magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Tenforde, T.S.

    1994-06-01

    Mechanisms through which static magnetic fields interact with living systems are described and illustrated by selected experimental observations. These mechanisms include electrodynamic interactions with moving, ionic charges (blood flow and nerve impulse conduction), magnetomechanical interactions (orientation and translation of molecules structures and magnetic particles), and interactions with electronic spin states in charge transfer reactions (photo-induced electron transfer in photosynthesis). A general summary is also presented of the biological effects of static magnetic fields. There is convincing experimental evidence for magnetoreception mechanisms in several classes of lower organisms, including bacteria and marine organisms. However, in more highly evolved species of animals, there is no evidence that the interactions of static magnetic fields with flux densities up to 2 Tesla (1 Tesla [T] = 10{sup 4} Gauss) produce either behavioral or physiolocical alterations. These results, based on controlled studies with laboratory animals, are consistent with the outcome of recent epidemiological surveys on human populations exposed occupationally to static magnetic fields.

  9. Research program on the biological effects of oil pollution

    International Nuclear Information System (INIS)

    Barrett, R.T.

    1991-12-01

    A national research program on the biological effects of oil pollution (FOBO) was initiated by the Norwegian Ministry of Environment in October 1983 in the light of the increasing oil exploration and production activity in the North Sea and northern Norwegian waters. Ambitions were high and five main fields of research were suggested: Seabirds, fish (incl. salmon), marine mammals, the littoral zone and plankton. However, due to the lack of interest on the part of other potential financers, e.g. the Ministry of Fisheries and the oil companies, to participate, the four-year programme had to be limited to the following three topics: Seabirds around bruding colonies and at sea; Higher plants along the shoreline; The littoral zone. The program ran from the autumn of 1985 to the end of 1989 and this report summarizes the main results and conclusions of each project. 95 refs., 52 figs., 9 tabs

  10. Effects of biological sex on the pathophysiology of the heart.

    Science.gov (United States)

    Fazal, Loubina; Azibani, Feriel; Vodovar, Nicolas; Cohen Solal, Alain; Delcayre, Claude; Samuel, Jane-Lise

    2014-02-01

    Cardiovascular diseases are the leading causes of death in men and women in industrialized countries. While the effects of biological sex on cardiovascular pathophysiology have long been known, the sex-specific mechanisms mediating these processes have been further elucidated over recent years. This review aims at analysing the sex-based differences in cardiac structure and function in adult mammals, and the sex-based differences in the main molecular mechanisms involved in the response of the heart to pathological situations. It emerged from this review that the sex-based difference is a variable that should be dealt with, not only in basic science or clinical research, but also with regards to therapeutic approaches. © 2013 The British Pharmacological Society.

  11. Challenges in Analyzing the Biological Effects of Resveratrol

    DEFF Research Database (Denmark)

    Erdogan, Cihan Süleyman; Vang, Ole

    2016-01-01

    The suggested health effects (e.g., disease prevention) of dietary bioactive compounds such as resveratrol are challenging to prove in comparison to man-made drugs developed for therapeutic purposes. Dietary bioactive compounds have multiple cellular targets and therefore have a variety of biolog......The suggested health effects (e.g., disease prevention) of dietary bioactive compounds such as resveratrol are challenging to prove in comparison to man-made drugs developed for therapeutic purposes. Dietary bioactive compounds have multiple cellular targets and therefore have a variety...... research. Questions we address include: (1) Is the combinatorial effect of resveratrol and other compounds real? (2) What are the real and relevant doses of resveratrol after administration? and (3) Is it possible to estimate the preventive effect of resveratrol by clinical trials using standard...... experimental designs? The examples concerning resveratrol taken from the scientific literature are mainly from 2010 and later. The challenges pointed out in this review are similar to most naturally occurring bioactive compounds...

  12. Biological effects of carvacrol and cinnamaldehyde on Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    Angélique Montagu

    2016-07-01

    Full Text Available Acinetobacter baumannii has emerged as a major cause of nosocomial infections. The ability of A. baumannii to display various resistance mechanisms against antibiotics has transformed it into a successful nosocomial pathogen. The limited number of antibiotics in development and the disengagement of the pharmaceutical industry have prompted the development of innovative strategies. One of these strategies is the use of essential oils, especially aromatic compounds that are potent antibacterial molecules. Among them, the combination of carvacrol and cinnamaldehyde has already demonstrated antibacterial efficacy against A. baumannii. The aim of this study was to determine the biological effects of these two compounds in A. baumannii, describing their effect on the rRNA and gene regulation under environmental stress conditions. Results demonstrated rRNA degradation by the carvacrol/cinnamaldehyde mixture, and this effect was due to carvacrol. Degradation was conserved after encapsulation of the mixture in lipid nanocapsules. Results showed an upregulation of the genes coding for heat shock proteins, such as groES, groEL, dnaK, clpB and the catalase katE, after exposure to carvacrol/cinnamaldehyde mixture. The catalase was upregulated after carvacrol exposure wich is related to an oxidative stress. The combination of thiourea (hydroxyl radical scavenger and carvacrol demonstrated a potent bactericidal effect. These results underline the development of defense strategies of the bacteria by synthesis of reactive oxygen species (ROS in response to environmental stress conditions, such as carvacrol.

  13. Biological effects due to weak magnetic fields on plants

    Science.gov (United States)

    Belyavskaya, N.

    In the evolution process, living organisms have experienced the action of the Earth's magnetic field (MF) that is a natural component of our environment. It is known that a galactic MF induction does not exceed 0.1 nT, since investigations of weak magnetic field (WMF) effects on biological systems have attracted attention of biologists due to planning long-term space flights to other planets where the magnetizing force is near 10-5 Oe. However, the role of WMF and its influence on organisms' functioning are still insufficiently investigated. A large number of experiments with seedlings of different plant species placed in WMF has found that the growth of their primary roots is inhibited during the early terms of germination in comparison with control. The proliferation activity and cell reproduction are reduced in meristem of plant roots under WMF application. The prolongation of total cell reproductive cycle is registered due to the expansion of G phase in1 different plant species as well as of G phase in flax and lentil roots along with2 relative stability of time parameters of other phases of cell cycle. In plant cells exposed to WMF, the decrease in functional activity of genome at early prereplicate period is shown. WMF causes the intensification in the processes of proteins' synthesis and break-up in plant roots. Qualitative and quantitative changes in protein spectrum in growing and differentiated cells of plant roots exposed to WMF are revealed. At ultrastructural level, there are observed such ultrastructural peculiarities as changes in distribution of condensed chromatin and nucleolus compactization in nuclei, noticeable accumulation of lipid bodies, development of a lytic compartment (vacuoles, cytosegresomes and paramural bodies), and reduction of phytoferritin in plastids in meristem cells of pea roots exposed to WMF. Mitochondria are the most sensitive organelle to WMF application: their size and relative volume in cells increase, matrix is electron

  14. A Locomotor Deficit Induced by Sublethal Doses of Pyrethroid and Neonicotinoid Insecticides in the Honeybee Apis mellifera.

    Science.gov (United States)

    Charreton, Mercédès; Decourtye, Axel; Henry, Mickaël; Rodet, Guy; Sandoz, Jean-Christophe; Charnet, Pierre; Collet, Claude

    2015-01-01

    The toxicity of pesticides used in agriculture towards non-targeted organisms and especially pollinators has recently drawn the attention from a broad scientific community. Increased honeybee mortality observed worldwide certainly contributes to this interest. The potential role of several neurotoxic insecticides in triggering or potentiating honeybee mortality was considered, in particular phenylpyrazoles and neonicotinoids, given that they are widely used and highly toxic for insects. Along with their ability to kill insects at lethal doses, they can compromise survival at sublethal doses by producing subtle deleterious effects. In this study, we compared the bee's locomotor ability, which is crucial for many tasks within the hive (e.g. cleaning brood cells, feeding larvae…), before and after an acute sublethal exposure to one insecticide belonging to the two insecticide classes, fipronil and thiamethoxam. Additionally, we examined the locomotor ability after exposure to pyrethroids, an older chemical insecticide class still widely used and known to be highly toxic to bees as well. Our study focused on young bees (day 1 after emergence) since (i) few studies are available on locomotion at this stage and (ii) in recent years, pesticides have been reported to accumulate in different hive matrices, where young bees undergo their early development. At sublethal doses (SLD48h, i.e. causing no mortality at 48 h), three pyrethroids, namely cypermethrin (2.5 ng/bee), tetramethrin (70 ng/bee), tau-fluvalinate (33 ng/bee) and the neonicotinoid thiamethoxam (3.8 ng/bee) caused a locomotor deficit in honeybees. While the SLD48h of fipronil (a phenylpyrazole, 0.5 ng/bee) had no measurable effect on locomotion, we observed high mortality several days after exposure, an effect that was not observed with the other insecticides. Although locomotor deficits observed in the sublethal range of pyrethroids and thiamethoxam would suggest deleterious effects in the field, the case of

  15. A Locomotor Deficit Induced by Sublethal Doses of Pyrethroid and Neonicotinoid Insecticides in the Honeybee Apis mellifera.

    Directory of Open Access Journals (Sweden)

    Mercédès Charreton

    Full Text Available The toxicity of pesticides used in agriculture towards non-targeted organisms and especially pollinators has recently drawn the attention from a broad scientific community. Increased honeybee mortality observed worldwide certainly contributes to this interest. The potential role of several neurotoxic insecticides in triggering or potentiating honeybee mortality was considered, in particular phenylpyrazoles and neonicotinoids, given that they are widely used and highly toxic for insects. Along with their ability to kill insects at lethal doses, they can compromise survival at sublethal doses by producing subtle deleterious effects. In this study, we compared the bee's locomotor ability, which is crucial for many tasks within the hive (e.g. cleaning brood cells, feeding larvae…, before and after an acute sublethal exposure to one insecticide belonging to the two insecticide classes, fipronil and thiamethoxam. Additionally, we examined the locomotor ability after exposure to pyrethroids, an older chemical insecticide class still widely used and known to be highly toxic to bees as well. Our study focused on young bees (day 1 after emergence since (i few studies are available on locomotion at this stage and (ii in recent years, pesticides have been reported to accumulate in different hive matrices, where young bees undergo their early development. At sublethal doses (SLD48h, i.e. causing no mortality at 48 h, three pyrethroids, namely cypermethrin (2.5 ng/bee, tetramethrin (70 ng/bee, tau-fluvalinate (33 ng/bee and the neonicotinoid thiamethoxam (3.8 ng/bee caused a locomotor deficit in honeybees. While the SLD48h of fipronil (a phenylpyrazole, 0.5 ng/bee had no measurable effect on locomotion, we observed high mortality several days after exposure, an effect that was not observed with the other insecticides. Although locomotor deficits observed in the sublethal range of pyrethroids and thiamethoxam would suggest deleterious effects in the field

  16. Biological mechanisms of radiation effects; Biologische Mechanismen der Strahlenwirkung

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, S.; Doerr, W. [Medizinische Universitaet Wien, ATRAB - Angewandte und Translationale Radiobiologie, Univ.-Klinik fuer Strahlentherapie, Wien (Austria)

    2017-07-15

    Exposure to ionizing radiation for diagnostic purposes is inevitable in modern medicine. The therapeutic application of irradiation is highly effective against cancer; however, this implies exposure of normal tissue structures to significant doses of radiation. Diagnostic or therapeutic exposure to ionizing radiation can result in tissue changes and tumor induction in the long term. Knowledge of the biological mechanisms underlying these effects is essential for individualization of the application. This article examines the biological mechanisms at the tissue and molecular level, the clinical manifestation of radiation effects, dose-dependence of the risk and the temporal progression as well as influencing factors. The time course of the reaction of tissues to radiation exposure extends over wide ranges up to many decades. The effects of radiation on tissues are classified into early and late and their pathobiology is significantly different. Various factors (R) influencing the clinical manifestation of radiation effects have been identified related to the exposure pattern. The radiation tolerance of normal tissue structures regarding the induction of functional deficits shows great variation but always has a threshold value, which is usually not exceeded in diagnostic procedures. The risk of a radiation-induced fatal malignancy (total body exposure 5%/Gy) for a medical administration of radiation must be considered as very low in comparison to the natural risks. Informed consent of patients must reflect this in a balanced way. (orig.) [German] Eine Exposition mit ionisierender Strahlung fuer diagnostische Zwecke ist in der modernen Medizin unumgaenglich. Bei einer Tumorerkrankung ist die therapeutische Anwendung dieser Strahlung hoch effektiv. Dies impliziert immer eine Exposition normaler Gewebestrukturen mit signifikanten Strahlendosen. Die diagnostische oder therapeutische Exposition mit ionisierender Strahlung kann langfristig zu Gewebeveraenderungen und

  17. Determining environmental causes of biological effects: the need for a mechanistic physiological dimension in conservation biology.

    Science.gov (United States)

    Seebacher, Frank; Franklin, Craig E

    2012-06-19

    The emerging field of Conservation Physiology links environmental change and ecological success by the application of physiological theory, approaches and tools to elucidate and address conservation problems. Human activity has changed the natural environment to a point where the viability of many ecosystems is now under threat. There are already many descriptions of how changes in biological patterns are correlated with environmental changes. The next important step is to determine the causative relationship between environmental variability and biological systems. Physiology provides the mechanistic link between environmental change and ecological patterns. Physiological research, therefore, should be integrated into conservation to predict the biological consequences of human activity, and to identify those species or populations that are most vulnerable.

  18. The biological effects of exposure to ionising radiation

    International Nuclear Information System (INIS)

    Higson, D.J.

    2016-01-01

    Scenarios for exposure to ionising radiation range from natural background radiation (chronic) to the explosions of atomic bombs (acute), with some medical, industrial and research exposures lying between these extremes. Biological responses to radiation that predominate at high doses incurred at high dose rates are different from those that predominate at low doses and low dose rates. Single doses from bomb explosions ranged up to many thousand mGy. Acute doses greater than about 1000 mGy cause acute radiation syndrome (ARS). Below this threshold, radiation has a variety of potential latent health effects: Change to the incidence of cancer is the most usual subject of attention but change to longevity may be the best overall measure because decreased incidences of non-cancer mortality have been observed to coincide with increased incidence of cancer mortality. Acute doses greater than 500 mGy cause increased risks of cancer and decreased life expectancy. For doses less than 100 mGy, beneficial overall health effects ('radiation hormesis') have been observed. At the other end of the spectrum, chronic exposure to natural radiation has occurred throughout evolution and is necessary for the normal life and health of current species. Dose rates greater than the present global average of about 2 mGy per year have either no discernible health effect or beneficial health effects up to several hundred mGy per year. It is clearly not credible that a single health effects model -- such as the linear no-threshold (LNT) model of risk estimation -- could fit all latent health effects. A more realistic model is suggested.

  19. Assessing Sub-Lethal Impacts of Petroleum Compounds on Marine Benthic Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, J. Fredrik

    2012-07-01

    Petroleum and its different distillates commonly end up in the marine environment. One source of these additions is discharges originating from shipping activities; accidents, ship wrecks, operational spills etc. Depending on several different factors that govern the fate of petroleum released into the marine environment the effects of the discharge will differ, from acute toxic to long term sub-lethal effects. While effects on biota from large spills have thoroughly been investigated in the past long term sub-lethal effects are somewhat less examined. Therefore the objective of this thesis has been to develop and apply a method to analyze what effects low concentrations of petroleum, which often ends up in marine sediments, have on benthic sediment biota. Ecotoxicological endpoints that were evaluated were density changes of meiofauna and variations in the microbial community function, measured as inorganic nutrient fluxes over the sediment-water interface the potential to perform a metabolic process. These types of organisms are two important key players in marine benthic sedimentary habitats, performing ecosystem services such as degradation of organic matter, recycling of nutrients and various pollutants and they constitute a carbon link to higher trophic levels. As manual classification of meiofauna is very time-consuming process including an extended learning process for the taxonomist, this thesis is in its first part focused at the field of automatic classification. To classify meiofaunal communities a novel technique was developed where the image analysis software ZooImage was adapted to automatically classify higher taxonomic taxa of meiofauna, with successful results. The technique was evaluated by classifying meiofaunal communities from five different depths in the Gullmar Fjord, Sweden. The accuracy of the analyses was tested using ZooImage's internal 10-fold cross-validation method, and by comparing digitalized samples from the different sites

  20. The relative biological effectiveness of I-125 and Pd-103

    International Nuclear Information System (INIS)

    Ling, C. Clifton; Li, William X.; Anderson, Lowell L.

    1995-01-01

    Purpose: To determine the relative biological effectiveness (RBE) of I-125 and Pd-103 relative to Co-60. Methods and Materials: A cell line REC:ras, derived from rat embryo cells, was used. Cells in exponential or plateau phase were irradiated at dose rates of about 0.07 Gy/h and 0.14 Gy/h. To circumvent the interface effect, cells were grown and irradiated on membranes made of cellulose acetate, which has an effective Z of 7.5. I-125 and Pd-103 seeds were placed in a custom designed template that yielded a homogeneous dose distribution in the plane of the cell culture. The dose rates of irradiation were measured by calibrated thermoluminescence dosimetry (TLD) chips. Results and Conclusions: Our measurements yielded an RBE of about 1.4 for I-125 at dose rates of about 0.07 Gy/h, and an RBE of about 1.9 for Pd-103 at dose rates of about 0.07 Gy/h and 0.14 Gy/h. The RBE of I-125 is similar to those measured by other investigators, the RBE for Pd-103 is being reported for the first time

  1. Hydrodynamic effects in laser cutting of biological tissue phantoms

    Science.gov (United States)

    Zhigarkov, V. S.; Yusupov, V. I.; Tsypina, S. I.; Bagratashvili, V. N.

    2017-11-01

    We study the thermal and transport processes that occur in the course of incision formation at the surface of a biological tissue phantom under the action of near-IR, moderate-power, continuous-wave laser radiation (λ = 1.94 μm) delivered by means of an optical fibre with an absorbing coating on its exit face. It is shown that in addition to the thermal effect, the laser-induced hydrodynamic effects caused by the explosive boiling of the interstitial water make a large contribution to the phantom destruction mechanism. These effects lead to the tissue rupture accompanied by the ejection of part of the fragmented substance from the site of laser impact and the formation of highly porous structure near the incision surface. We have found that the depth, the width and the relief of the laser incision wall in the case of using the optical fibre moving with a constant velocity, depend on the fibre tilt angle with respect to the phantom surface, as well as the direction of the fibre motion.

  2. Formamidopyrimidines in DNA: mechanisms of formation, repair, and biological effects.

    Science.gov (United States)

    Dizdaroglu, Miral; Kirkali, Güldal; Jaruga, Pawel

    2008-12-15

    Oxidatively induced damage to DNA results in a plethora of lesions comprising modified bases and sugars, DNA-protein cross-links, tandem lesions, strand breaks, and clustered lesions. Formamidopyrimidines, 4,6-diamino-5-formamidopyrimidine (FapyAde) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua), are among the major lesions generated in DNA by hydroxyl radical attack, UV radiation, or photosensitization under numerous in vitro and in vivo conditions. They are formed by one-electron reduction of C8-OH-adduct radicals of purines and thus have a common precursor with 8-hydroxypurines generated upon one-electron oxidation. Methodologies using mass spectrometry exist to accurately measure FapyAde and FapyGua in vitro and in vivo. Formamidopyrimidines are repaired by base excision repair. Numerous prokaryotic and eukaryotic DNA glycosylases are highly specific for removal of these lesions from DNA in the first step of this repair pathway, indicating their biological importance. FapyAde and FapyGua are bypassed by DNA polymerases with the insertion of the wrong intact base opposite them, leading to mutagenesis. In mammalian cells, the mutagenicity of FapyGua exceeds that of 8-hydroxyguanine, which is thought to be the most mutagenic of the oxidatively induced lesions in DNA. The background and formation levels of the former in vitro and in vivo equal or exceed those of the latter under various conditions. FapyAde and FapyGua exist in living cells at significant background levels and are abundantly generated upon exposure to oxidative stress. Mice lacking the genes that encode specific DNA glycosylases accumulate these lesions in different organs and, in some cases, exhibit a series of pathological conditions including metabolic syndrome and cancer. Animals exposed to environmental toxins accumulate formamidopyrimidines in their organs. Here, we extensively review the mechanisms of formation, measurement, repair, and biological effects of formamidopyrimidines

  3. Enhanced Biological Phosphorus Removal: Metabolic Insights and Salinity Effects

    OpenAIRE

    Welles, L.

    2015-01-01

    Enhanced biological phosphorus removal (EBPR) is a biological process for efficient phosphate removal from wastewaters through intracellular storage of polyphosphate by polyphosphate-accumulating organisms (PAO) and subsequent removal of PAO from the system through wastage of sludge. In comparison to physical and chemical phosphorus removal processes, the biological process has several advantages such as high removal efficiency, low cost, and no chemical sludge production, but disturbances an...

  4. Relative biological efficiency of 592 MeV protons. Analysis of the biological effect of secondary radiation

    International Nuclear Information System (INIS)

    Legeay, G.; Baarli, J.

    1968-01-01

    The relative biological efficiency (RBE) of high energy protons is of importance because of their effects in the field of radioprotection around large accelerators and during space-flights. The nature of the interactions between 592 MeV protons and biological tissues makes it necessary to take into consideration the contribution of secondary radiation to the biological effect. Since it is not possible to obtain from a synchrotron a beam having a sufficiently large cross-section to irradiate large animals, one has to resort to certain devices concerning the mode of exposure when small laboratory animals are used. By irradiating rats individually and in groups, and by using the lethal test as a function of time, the authors show that the value of the RBE is different for animals of the same species having the same biological parameters. Thus there appears an increase in the biological effect due to secondary radiation produced in nuclear cascades which develop in a large volume, for example that of a human being. (author) [fr

  5. Relative biological effectiveness if alpha radiation for human lung exposure

    International Nuclear Information System (INIS)

    Yarmoshenko, I.; Kirdin, I.; Zhukovsky, M.

    2006-01-01

    Full text of publication follows: The concept of RBE, which introduced by ICRP and ICRU about 50 years ago to compare biological effects of ionizing radiation of different types, still continues to be the essential element of current and projected radiation protection systems in terms of deriving quantities (quality factor and radiation weighting factor). For example, RBE for the stochastic effects induction has to be considered for appropriate radiation weighting of the absorbed dose while estimating equivalent dose. Simulation of lung cancer radiation risk for the cases of inhalation of radon progeny and incorporation of plutonium in lung in comparison with external reference radiation allows assessment of RBE for alpha-radiation. Specific radiation risk models were developed by results of the direct epidemiological studies and used for such simulation. Simulation included published risk models for nuclear workers of the Mayak facilities in the former Soviet Union exposed to incorporated plutonium (Kreisheimer et al., 2003; Gilbert et al., 2004) and underground miners exposed to radon progenies (BEIR VI, 1999). Additionally lung cancer risk model was developed for a case of population indoor radon exposure. Lung cancer risk related to external exposure is estimated using the risk model develop ed using data of Life Span Study of Japanese atomic bomb survivors. By results of lifetime lung cancer risk simulation using Monte Carlo approach estimated median value of RBE in case of indoor radon exposure is 1.5 (with 90% range 0.4 to 7). In case of the two models developed by BEIR VI for lung cancer risk due to radon exposure in underground miners the median values of RBE are 2.1 and 4.4 (with 90% ranges 0.3 to 17 and 0.7 to 45) respectively.Two different models for lung cancer risk related to plutonium exposure resulted in close estimates of RBE: median value of 12 and 13 (with 90% range 4 to 104 and 4 to 136) respectively. Considerable discrepancy between RBE

  6. Sublethal effects of industrial chemicals on fish fingerlings (Tilapia ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-22

    Mar 22, 2010 ... Key words: Tilapia guineensis, industrial chemical, bioaccumulation, surfactants. ... product that has acceptable stability in oil pipelines. (Patton, 1995). .... assays were assessed with the two-factor ANOVA (analysis of.

  7. Sublethal effects of manganese on the carbohydrate metabolism of ...

    African Journals Online (AJOL)

    Carbohydrate metabolism provides (1) energy,. (2) precursors for synthetic reactions ... as a response to the adrenal corticotrophic hormone (ACTH) from the ... During the exposure experiments, control groups were also set-up. The control fish ...

  8. Sublethal Effects of Diesel on Total Protein Levels and Cholesterol ...

    African Journals Online (AJOL)

    Michael Horsfall

    were handpicked at the Eagle Cement area of the New Calabar River and subjected to different levels ... groups when compared to the control in both the muscle and the viscera of the periwinkle. ... In Nigeria, oil industry operations are both offshore and onshore. ... This acts as a means of assessing the hazard or potential ...

  9. Sublethal effects of temperature on freshwater organisms, with ...

    African Journals Online (AJOL)

    or species may manifest at higher levels of the hierarchy, namely, populations, communities and entire ..... the field, acclimated and then transferred to aerated containers, ...... availability interact to mediate growth and body stoichiometry in a.

  10. Contact Irritant Responses of Aedes aegypti Using Sublethal Concentration and Focal Application of Pyrethroid Chemicals

    OpenAIRE

    Manda, Hortance; Shah, Pankhil; Polsomboon, Suppaluck; Chareonviriyaphap, Theeraphap; Castro-Llanos, Fanny; Morrison, Amy; Burrus, Roxanne G.; Grieco, John P.; Achee, Nicole L.

    2013-01-01

    BACKGROUND: Previous studies have demonstrated contact irritant and spatial repellent behaviors in Aedes aegypti following exposure to sublethal concentrations of chemicals. These sublethal actions are currently being evaluated in the development of a push-pull strategy for Ae. aegypti control. This study reports on mosquito escape responses after exposure to candidate chemicals for a contact irritant focused push-pull strategy using varying concentrations and focal application. METHODS: Cont...

  11. Scientific projection paper on biologic effects of ionizing radiation

    International Nuclear Information System (INIS)

    Matanoski, G.

    1980-01-01

    There is widespread knowledge about the effects of radiation in human populations but the studies have had some limitations which have left gaps in our knowledge. Most populations have had exposure to high doses with little information on the effect of dose rate. The characteristics of the populations have been restricted by the location of the disaster, the occupational limitations, or the basic risks associated with the under-lying disease for which radiation was given. All doses have been estimated and such values are subject to marked variability particularly when they rely on sources of data such as hospital records. The biological data although extensive have several deficits in information. Which are the sites in which cancer is produced by irradiation and what are the cell types which are produced. The sensitivity of various tissues and organs are not similar and it is important to rank them according to susceptibility. This has been done in the past but the results are not complete for all cell types and organs. The temporal patterns for tumor development, the latent period, the period of expressed excess, the life-time risks need to be defined more precisely for the cancers. Many populations have not been followed long enough to express the complete risk

  12. Biological and sanitary effects of non ionizing radiations

    International Nuclear Information System (INIS)

    Brugere, H.; Hours, M.; Seze, R. de; Bernier, M.; Letertre, Th.; Aurengo, A.; Burais, N.; Bedja, M.; Merckel, O.; Decat, G.; Lagroye, I.; Perrin, A.; Poulletier de Gannes, F.; Aurengo, A.; Souques, M.; Cesarini, J.P.; Lagroye, I.; Aurengo, A.; Cesarini, J.P.

    2008-01-01

    The objective of this day was to encourage the collaborations, especially multidisciplinary, on the biological, clinical, epidemiological and dosimetry aspects. The different presentations are as follow: the magneto reception among animals; the health and radio frequencies foundation; expo-metry to radio frequency fields: dosemeters evaluation; the electro-optical probes as tool of hyper frequency dosimetry; characterisation of emissions produced by the low consumption fluo-compact lamps in the perspective of persons exposure; strong and weak points of epidemiology; numerical dosimetry in low frequency magnetic and/or electric field; exposure of the French population to the 50 Hz magnetic field: first results for the Ile-de-france and Rhone alpes areas; characterisation of the exposure to the very low frequency magnetic fields in the town of Champlan; measurement of the residential exposure of children to the extremely low frequency, very low frequency and radiofrequency (E.L.F., V.L.F. and R.F.) fields and modeling of the high voltage magnetic field face to the child leukemia; effects of radiofrequency signals of wireless communications on the young animals; study of combined effects of 2.45 GHz microwaves and a known mutagen on DNA by two different approaches; effects on the oxidizing stress of nervous cells exposure to an (enhanced data rates for GSM evolution) E.D.G.E. signal; is environmental epidemiology still a science; cardiac implants and exposure to 50 Hz electromagnetic fields in occupational environment; the tanning by artificial UV radiation: norms and legislation; mobiles phones, Wi Fi and other wireless communications; effects on health of 50-60 Hz electromagnetic fields; natural and artificial ultraviolet radiations: a proved risk. (N.C.)

  13. Toxic and hormetic-like effects of three components of citrus essential oils on adult Mediterranean fruit flies (Ceratitis capitata.

    Directory of Open Access Journals (Sweden)

    Stella A Papanastasiou

    Full Text Available Plant essential oils (EOs and a wide range of their individual components are involved in a variety of biological interactions with insect pests including stimulatory, deterrent, toxic and even hormetic effects. Both the beneficial and toxic properties of citrus EOs on the Mediterranean fruit fly (medfly have been experimentally evidenced over the last years. However, no information is available regarding the toxic or beneficial effects of the major components of citrus EOs via contact with the adults of the Mediterranean fruit fly. In the present study, we explored the toxicity of limonene, linalool and α-pinene (3 of the main compounds of citrus EOs against adult medflies and identified the effects of sub-lethal doses of limonene on fitness traits in a relaxed [full diet (yeast and sugar] and in a stressful (sugar only feeding environment. Our results demonstrate that all three compounds inferred high toxicity to adult medflies regardless of the diet, with males being more sensitive than females. Sub-lethal doses of limonene (LD20 enhanced the lifespan of adult medflies when they were deprived of protein. Fecundity was positively affected when females were exposed to limonene sub-lethal doses. Therefore, limonene, a major constituent of citrus EOs, induces high mortality at increased doses and positive effects on life history traits of medfly adults through contact at low sub-lethal doses. A hormetic-like effect of limonene to adult medflies and its possible underlying mechanisms are discussed.

  14. Biological effects of radiation human health and safety

    International Nuclear Information System (INIS)

    1977-05-01

    The biological hazards of nuclear energy usage are a growing source of public concern. The medical profession may well be expected to contribute to public debate on the issue. This document, therefore, attempts a balanced review of the known and suspected human biological consequences of exposure to different types of ionizing radiation, emphasizing in particular the nuclear industry

  15. The biological effects of ionising radiation on Crustaceans: A review

    International Nuclear Information System (INIS)

    Fuller, Neil; Lerebours, Adélaïde; Smith, Jim T.; Ford, Alex T.

    2015-01-01

    Highlights: • We comprehensively review the effects of ionising radiation in crustaceans. • Current environmental radioprotection levels found to be inadequate in some cases. • Mutation is shown to be a sensitive endpoint of radiation exposure. • Lowest observed effect dose rate varies by orders of magnitude. - Abstract: Historic approaches to radiation protection are founded on the conjecture that measures to safeguard humans are adequate to protect non-human organisms. This view is disparate with other toxicants wherein well-developed frameworks exist to minimise exposure of biota. Significant data gaps for many organisms, coupled with high profile nuclear incidents such as Chernobyl and Fukushima, have prompted the re-evaluation of our approach toward environmental radioprotection. Elucidating the impacts of radiation on biota has been identified as priority area for future research within both scientific and regulatory communities. The crustaceans are ubiquitous in aquatic ecosystems, comprising greater than 66,000 species of ecological and commercial importance. This paper aims to assess the available literature of radiation-induced effects within this subphylum and identify knowledge gaps. A literature search was conducted pertaining to radiation effects on four endpoints as stipulated by a number of regulatory bodies: mortality, morbidity, reproduction and mutation. A major finding of this review was the paucity of data regarding the effects of environmentally relevant radiation doses on crustacean biology. Extremely few studies utilising chronic exposure durations or wild populations were found across all four endpoints. The dose levels at which effects occur was found to vary by orders of magnitude thus presenting difficulties in developing phyla-specific benchmark values and reference levels for radioprotection. Based on the limited data, mutation was found to be the most sensitive endpoint of radiation exposure, with mortality the least sensitive

  16. The biological effects of ionising radiation on Crustaceans: A review

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Neil; Lerebours, Adélaïde [Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Ferry Road, Portsmouth, Hampshire PO4 9LY (United Kingdom); Smith, Jim T. [School of Earth & Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth, Hampshire PO1 3QL (United Kingdom); Ford, Alex T., E-mail: alex.ford@port.ac.uk [Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Ferry Road, Portsmouth, Hampshire PO4 9LY (United Kingdom)

    2015-10-15

    Highlights: • We comprehensively review the effects of ionising radiation in crustaceans. • Current environmental radioprotection levels found to be inadequate in some cases. • Mutation is shown to be a sensitive endpoint of radiation exposure. • Lowest observed effect dose rate varies by orders of magnitude. - Abstract: Historic approaches to radiation protection are founded on the conjecture that measures to safeguard humans are adequate to protect non-human organisms. This view is disparate with other toxicants wherein well-developed frameworks exist to minimise exposure of biota. Significant data gaps for many organisms, coupled with high profile nuclear incidents such as Chernobyl and Fukushima, have prompted the re-evaluation of our approach toward environmental radioprotection. Elucidating the impacts of radiation on biota has been identified as priority area for future research within both scientific and regulatory communities. The crustaceans are ubiquitous in aquatic ecosystems, comprising greater than 66,000 species of ecological and commercial importance. This paper aims to assess the available literature of radiation-induced effects within this subphylum and identify knowledge gaps. A literature search was conducted pertaining to radiation effects on four endpoints as stipulated by a number of regulatory bodies: mortality, morbidity, reproduction and mutation. A major finding of this review was the paucity of data regarding the effects of environmentally relevant radiation doses on crustacean biology. Extremely few studies utilising chronic exposure durations or wild populations were found across all four endpoints. The dose levels at which effects occur was found to vary by orders of magnitude thus presenting difficulties in developing phyla-specific benchmark values and reference levels for radioprotection. Based on the limited data, mutation was found to be the most sensitive endpoint of radiation exposure, with mortality the least sensitive

  17. Effect of Process-Oriented Guided-Inquiry Learning on Non-majors Biology Students' Understanding of Biological Classification

    Science.gov (United States)

    Wozniak, Breann M.

    The purpose of this study was to examine the effect of process-oriented guided-inquiry learning (POGIL) on non-majors college biology students' understanding of biological classification. This study addressed an area of science instruction, POGIL in the non-majors college biology laboratory, which has yet to be qualitatively and quantitatively researched. A concurrent triangulation mixed methods approach was used. Students' understanding of biological classification was measured in two areas: scores on pre and posttests (consisting of 11 multiple choice questions), and conceptions of classification as elicited in pre and post interviews and instructor reflections. Participants were Minnesota State University, Mankato students enrolled in BIOL 100 Summer Session. One section was taught with the traditional curriculum (n = 6) and the other section in the POGIL curriculum (n = 10) developed by the researcher. Three students from each section were selected to take part in pre and post interviews. There were no significant differences within each teaching method (p familiar animal categories and aquatic habitats, unfamiliar organisms, combining and subdividing initial groupings, and the hierarchical nature of classification. The POGIL students were the only group to surpass these challenges after the teaching intervention. This study shows that POGIL is an effective technique at eliciting students' misconceptions, and addressing these misconceptions, leading to an increase in student understanding of biological classification.

  18. The effect of network biology on drug toxicology

    DEFF Research Database (Denmark)

    Gautier, Laurent; Taboureau, Olivier; Audouze, Karine Marie Laure

    2013-01-01

    Introduction: The high failure rate of drug candidates due to toxicity, during clinical trials, is a critical issue in drug discovery. Network biology has become a promising approach, in this regard, using the increasingly large amount of biological and chemical data available and combining...... it with bioinformatics. With this approach, the assessment of chemical safety can be done across multiple scales of complexity from molecular to cellular and system levels in human health. Network biology can be used at several levels of complexity. Areas covered: This review describes the strengths and limitations...... of network biology. The authors specifically assess this approach across different biological scales when it is applied to toxicity. Expert opinion: There has been much progress made with the amount of data that is generated by various omics technologies. With this large amount of useful data, network...

  19. Monitoring the effects of a lepidopteran insecticide, Flubendiamide, on the biology of a non-target dipteran insect, Drosophila melanogaster.

    Science.gov (United States)

    Sarkar, Saurabh; Roy, Sumedha

    2017-10-13

    Various organisms are adversely affected when subjected to chronic fluoride exposure. This highly electronegative ion present in several insecticide formulations is found to be lethal to target pests. In the present study, Drosophila melanogaster is treated with sub-lethal concentrations of a diamide insecticide formulation, Flubendiamide. Chronic exposure to the diamide (0.5-100 μg/mL) was found to be responsible for increase in fluoride ion concentration in larval as well as adult body fluid. Interestingly, 100 μg/mL Flubendiamide exposure resulted in 107 and 298% increase in fluoride ion concentration whereas only 23 and 52% of Flubendiamide concentration increase in larval and adult body fluid, respectively. Further, in this study, selected life cycle parameters like larval duration, pupal duration and emergence time showed minimal changes, whereas percentage of emergence and fecundity revealed significant treatment-associated variation. It can be noted that nearly 79% reduction in fecundity was observed with 100 μg/mL Flubendiamide exposure. The variations in these parameters indicate probable involvement of fluoride ion in detectable alterations in the biology of the non-target model insect, D. melanogaster. Furthermore, the outcomes of life cycle study suggest change in resource allocation pattern in the treated flies. The altered resource allocation might have been sufficient to resist changes in selective life cycle parameters, but it could not defend the changes in fecundity. The significant alterations indicate a definite trade-off pattern, where the treated individuals happen to compromise. Thus, survival is apparently taking an upper hand in comparison to reproductive ability in response to Flubendiamide exposure. Graphical abstract The figure demonstrates increase in Fluoride and Flubendiamide concentrations in Drosophila melanogaster after chronic sub-lethal exposure to Flubendiamide. Treatment-induced alterations in larval and pupal duration

  20. Frequent and seasonally variable sublethal anthrax infections are accompanied by short-lived immunity in an endemic system.

    Science.gov (United States)

    Cizauskas, Carrie A; Bellan, Steven E; Turner, Wendy C; Vance, Russell E; Getz, Wayne M

    2014-09-01

    Few studies have examined host-pathogen interactions in wildlife from an immunological perspective, particularly in the context of seasonal and longitudinal dynamics. In addition, though most ecological immunology studies employ serological antibody assays, endpoint titre determination is usually based on subjective criteria and needs to be made more objective. Despite the fact that anthrax is an ancient and emerging zoonotic infectious disease found world-wide, its natural ecology is not well understood. In particular, little is known about the adaptive immune responses of wild herbivore hosts against Bacillus anthracis. Working in the natural anthrax system of Etosha National Park, Namibia, we collected 154 serum samples from plains zebra (Equus quagga), 21 from springbok (Antidorcas marsupialis) and 45 from African elephants (Loxodonta africana) over 2-3 years, resampling individuals when possible for seasonal and longitudinal comparisons. We used enzyme-linked immunosorbent assays to measure anti-anthrax antibody titres and developed three increasingly conservative models to determine endpoint titres with more rigourous, objective mensuration. Between 52 and 87% of zebra, 0-15% of springbok and 3-52% of elephants had measurable anti-anthrax antibody titres, depending on the model used. While the ability of elephants and springbok to mount anti-anthrax adaptive immune responses is still equivocal, our results indicate that zebra in ENP often survive sublethal anthrax infections, encounter most B. anthracis in the wet season and can partially booster their immunity to B. anthracis. Thus, rather than being solely a lethal disease, anthrax often occurs as a sublethal infection in some susceptible hosts. Though we found that adaptive immunity to anthrax wanes rapidly, subsequent and frequent sublethal B. anthracis infections cause maturation of anti-anthrax immunity. By triggering host immune responses, these common sublethal infections may act as

  1. Effect of high linear energy transfer radiation on biological membranes

    International Nuclear Information System (INIS)

    Choudhary, D.; Srivastava, M.; Kale, R.K.; Sarma, A.

    1998-01-01

    Cellular membranes are vital elements, and their integrity is extremely essential for